Attempts to start proper implementation of the new action cost

# Conflicts:
#	src/main/java/net/knarcraft/blacksmith/BlacksmithPlugin.java
#	src/main/java/net/knarcraft/blacksmith/command/blacksmith/BlackSmithConfigCommand.java
#	src/main/java/net/knarcraft/blacksmith/formatting/BlacksmithStringFormatter.java
#	src/main/java/net/knarcraft/blacksmith/trait/SalvageSession.java
#	src/main/java/net/knarcraft/blacksmith/trait/ScrapperTrait.java

pom.xml

@@ -65,7 +65,7 @@
         <dependency>
             <groupId>org.spigotmc</groupId>
             <artifactId>spigot-api</artifactId>
-            <version>1.20.6-R0.1-SNAPSHOT</version>
+            <version>1.21.8-R0.1-SNAPSHOT</version>
             <scope>provided</scope>
         </dependency>
         <dependency>
@@ -83,7 +83,7 @@
         <dependency>
             <groupId>net.knarcraft</groupId>
             <artifactId>knarlib</artifactId>
-            <version>1.2.14</version>
+            <version>1.2.19</version>
             <scope>compile</scope>
         </dependency>
         <dependency>
@@ -92,6 +92,11 @@
             <version>5.10.2</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>net.objecthunter</groupId>
+            <artifactId>exp4j</artifactId>
+            <version>0.4.8</version>
+        </dependency>
     </dependencies>
 
     <!-- Build information -->
@@ -127,6 +132,10 @@
                                     <pattern>org.jetbrains.annotations</pattern>
                                     <shadedPattern>net.knarcraft.blacksmith.lib.annotations</shadedPattern>
                                 </relocation>
+                                <relocation>
+                                    <pattern>net.objecthunter.exp4j</pattern>
+                                    <shadedPattern>net.knarcraft.blacksmith.lib.exp4j</shadedPattern>
+                                </relocation>
                             </relocations>
                             <filters>
                                 <filter>
@@ -141,6 +150,12 @@
                                         <include>org/jetbrains/annotations/**</include>
                                     </includes>
                                 </filter>
+                                <filter>
+                                    <artifact>net.objecthunter:exp4j</artifact>
+                                    <includes>
+                                        <include>net/objecthunter/exp4j/**</include>
+                                    </includes>
+                                </filter>
                             </filters>
                         </configuration>
                     </execution>

src/main/java/net/knarcraft/blacksmith/BlacksmithPlugin.java

@@ -15,10 +15,12 @@ import net.knarcraft.blacksmith.command.scrapper.ScrapperEditCommand;
 import net.knarcraft.blacksmith.command.scrapper.ScrapperEditTabCompleter;
 import net.knarcraft.blacksmith.config.blacksmith.GlobalBlacksmithSettings;
 import net.knarcraft.blacksmith.config.scrapper.GlobalScrapperSettings;
+import net.knarcraft.blacksmith.container.ActionCost;
 import net.knarcraft.blacksmith.formatting.Translatable;
 import net.knarcraft.blacksmith.listener.NPCClickListener;
 import net.knarcraft.blacksmith.listener.PlayerListener;
 import net.knarcraft.blacksmith.manager.EconomyManager;
+import net.knarcraft.blacksmith.manager.PlayerUsageManager;
 import net.knarcraft.blacksmith.trait.BlacksmithTrait;
 import net.knarcraft.blacksmith.trait.ScrapperTrait;
 import net.knarcraft.knarlib.formatting.FormatBuilder;
@@ -28,7 +30,9 @@ import net.knarcraft.knarlib.formatting.Translator;
 import net.knarcraft.knarlib.plugin.ConfigCommentPlugin;
 import net.knarcraft.knarlib.util.ConfigHelper;
 import net.knarcraft.knarlib.util.UpdateChecker;
+import org.bukkit.Bukkit;
 import org.bukkit.configuration.file.FileConfiguration;
+import org.bukkit.configuration.serialization.ConfigurationSerialization;
 import org.bukkit.event.Event;
 import org.bukkit.plugin.PluginDescriptionFile;
 import org.bukkit.plugin.PluginManager;
@@ -122,6 +126,8 @@ public class BlacksmithPlugin extends ConfigCommentPlugin {
         instance = this;
         ConfigHelper.saveDefaults(this);
 
+        ConfigurationSerialization.registerClass(ActionCost.class);
+
         //Migrate from an earlier configuration file syntax if necessary 
         if (getConfig().getString("scrapper.defaults.dropItem") == null) {
             net.knarcraft.knarlib.util.ConfigHelper.migrateConfig(this);
@@ -148,6 +154,10 @@ public class BlacksmithPlugin extends ConfigCommentPlugin {
         //Alert about an update in the console
         UpdateChecker.checkForUpdate(this, "https://api.spigotmc.org/legacy/update.php?resource=105938",
                 () -> this.getDescription().getVersion(), null);
+
+        // Remove expired scrapper usage data
+        Bukkit.getScheduler().scheduleSyncRepeatingTask(this, () -> PlayerUsageManager.removeExpiredData(
+                System.currentTimeMillis() - 3600000), 36000, 36000);
     }
 
     /**

src/main/java/net/knarcraft/blacksmith/command/blacksmith/BlackSmithConfigCommand.java

@@ -12,6 +12,7 @@ import net.knarcraft.blacksmith.util.InputParsingHelper;
 import net.knarcraft.blacksmith.util.ItemHelper;
 import net.knarcraft.blacksmith.util.TypeValidationHelper;
 import org.bukkit.Material;
+import org.bukkit.NamespacedKey;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
 import org.bukkit.command.CommandSender;
@@ -100,8 +101,12 @@ public class BlackSmithConfigCommand implements CommandExecutor {
             if (enchantment == null) {
                 return false;
             }
+            NamespacedKey enchantmentKey = enchantment.getKeyOrNull();
+            if (enchantmentKey == null) {
+                return false;
+            }
             Translatable.getItemCurrentValueMessage(setting.getCommandName(),
-                    ItemType.ENCHANTMENT, enchantment.getKey().getKey(),
+                    ItemType.ENCHANTMENT, enchantmentKey.getKey(),
                     String.valueOf(settings.getEnchantmentCost(enchantment))).success(sender);
             return true;
         } else {
@@ -152,6 +157,8 @@ public class BlackSmithConfigCommand implements CommandExecutor {
                 return false;
             }
             ItemType itemType = ItemType.ENCHANTMENT;
+            // Note: While depreciated in Spigot, the new method is not available for Paper
+            @SuppressWarnings("deprecation")
             String itemChanged = enchantment.getKey().getKey();
             settings.setEnchantmentCost(enchantment, newPrice);
             Translatable.getItemValueChangedMessage(blacksmithSetting.getCommandName(), itemType, itemChanged, newValue).success(sender);

src/main/java/net/knarcraft/blacksmith/config/SettingValueType.java

@@ -55,4 +55,9 @@ public enum SettingValueType {
      */
     ENCHANTMENT_LIST,
 
+    /**
+     * Advanced cost, that supports either a simple double, or specifying money cost, permission requirement, exp cost and an item cost
+     */
+    ADVANCED_COST,
+
 }

src/main/java/net/knarcraft/blacksmith/config/blacksmith/GlobalBlacksmithSettings.java

@@ -523,6 +523,8 @@ public class GlobalBlacksmithSettings implements Settings<BlacksmithSetting> {
         //Load all enchantment prices
         ConfigurationSection enchantmentCostNode = getAndCreateSection(fileConfiguration, getBase(BlacksmithSetting.ENCHANTMENT_COST.getPath()));
         for (Enchantment enchantment : this.enchantmentCosts.keySet()) {
+            // Note: While depreciated in Spigot, the new method is not available for Paper
+            //noinspection deprecation
             enchantmentCostNode.set(unNormalizeName(enchantment.getKey().getKey()), this.enchantmentCosts.get(enchantment));
         }
 

src/main/java/net/knarcraft/blacksmith/config/scrapper/GlobalScrapperSettings.java

@@ -3,6 +3,7 @@ package net.knarcraft.blacksmith.config.scrapper;
 import net.knarcraft.blacksmith.BlacksmithPlugin;
 import net.knarcraft.blacksmith.config.SettingValueType;
 import net.knarcraft.blacksmith.config.Settings;
+import net.knarcraft.blacksmith.container.ActionCost;
 import net.knarcraft.blacksmith.util.ConfigHelper;
 import net.knarcraft.blacksmith.util.ItemHelper;
 import org.bukkit.Material;
@@ -113,18 +114,6 @@ public class GlobalScrapperSettings implements Settings<ScrapperSetting> {
         return ConfigHelper.asBoolean(getValue(setting));
     }
 
-    /**
-     * Gets the given value as a double
-     *
-     * <p>This will throw an exception if used for a non-double setting</p>
-     *
-     * @param setting <p>The setting to get the value of</p>
-     * @return <p>The value of the given setting as a double</p>
-     */
-    public double asDouble(@NotNull ScrapperSetting setting) {
-        return ConfigHelper.asDouble(getValue(setting));
-    }
-
     /**
      * Gets the value of a setting, using the default if not set
      *
@@ -190,8 +179,9 @@ public class GlobalScrapperSettings implements Settings<ScrapperSetting> {
      *
      * @return <p>The cost of using a scrapper to salvage an item</p>
      */
-    public double getSalvageCost() {
-        return asDouble(ScrapperSetting.SALVAGE_COST);
+    @NotNull
+    public ActionCost getSalvageCost() {
+        return getCost(ScrapperSetting.SALVAGE_COST, "salvage");
     }
 
     /**
@@ -199,8 +189,9 @@ public class GlobalScrapperSettings implements Settings<ScrapperSetting> {
      *
      * @return <p>The cost of using a scrapper to remove armor trim</p>
      */
-    public double getArmorTrimSalvageCost() {
-        return asDouble(ScrapperSetting.ARMOR_TRIM_SALVAGE_COST);
+    @NotNull
+    public ActionCost getArmorTrimSalvageCost() {
+        return getCost(ScrapperSetting.ARMOR_TRIM_SALVAGE_COST, "armor trim salvage");
     }
 
     /**
@@ -208,8 +199,46 @@ public class GlobalScrapperSettings implements Settings<ScrapperSetting> {
      *
      * @return <p>The cost of using a scrapper to remove netherite from an item</p>
      */
-    public double getNetheriteSalvageCost() {
-        return asDouble(ScrapperSetting.NETHERITE_SALVAGE_COST);
+    @NotNull
+    public ActionCost getNetheriteSalvageCost() {
+        return getCost(ScrapperSetting.NETHERITE_SALVAGE_COST, "netherite salvage");
+    }
+
+    /**
+     * Gets the cost of using a scrapper to split an enchanted book
+     *
+     * @return <p>The cost of using a scrapper to split an enchanted book</p>
+     */
+    @NotNull
+    public ActionCost getEnchantedBookSalvageCost() {
+        return getCost(ScrapperSetting.ENCHANTED_BOOK_SALVAGE_COST, "enchanted book salvage");
+    }
+
+    /**
+     * Gets the math formula for the increase in salvage cost
+     *
+     * @return <p>The salvage cost increase formula</p>
+     */
+    public String getSalvageCostIncrease() {
+        return asString(ScrapperSetting.SALVAGE_COST_INCREASE);
+    }
+
+    /**
+     * Gets the math formula for the increase in salvage cooldown
+     *
+     * @return <p>The salvage cooldown increase formula</p>
+     */
+    public String getSalvageCooldownIncrease() {
+        return asString(ScrapperSetting.SALVAGE_COOLDOWN_INCREASE);
+    }
+
+    /**
+     * Gets whether the enchanted book salvage price should be multiplied with the number of enchantments
+     *
+     * @return <p>Whether the enchanted book salvage price should be multiplied with the number of enchantments</p>
+     */
+    public boolean multiplyEnchantedBokSalvagePrice() {
+        return asBoolean(ScrapperSetting.MULTIPLY_ENCHANTED_BOOK_SALVAGE_COST);
     }
 
     /**
@@ -275,4 +304,35 @@ public class GlobalScrapperSettings implements Settings<ScrapperSetting> {
         }
     }
 
+    /**
+     * Gets the string value of the given setting
+     *
+     * @param setting <p>The setting to get the value of</p>
+     * @return <p>The value of the given setting as a string</p>
+     */
+    @NotNull
+    private String asString(@NotNull ScrapperSetting setting) {
+        return getValue(setting).toString();
+    }
+
+    /**
+     * Gets the action cost from the given scrapper setting
+     *
+     * @param setting  <p>The setting to get cost from</p>
+     * @param costType <p>Cost identifier for error message</p>
+     * @return <p>The cost of the action</p>
+     */
+    @NotNull
+    private ActionCost getCost(@NotNull ScrapperSetting setting, @NotNull String costType) {
+        Object value = getValue(setting);
+        if (value instanceof ActionCost actionCost) {
+            return actionCost;
+        } else if (value instanceof Double number) {
+            return new ActionCost(number);
+        } else {
+            BlacksmithPlugin.error("Unable to load " + costType + " cost! Cost set to free!");
+            return new ActionCost();
+        }
+    }
+
 }

src/main/java/net/knarcraft/blacksmith/config/scrapper/ScrapperNPCSettings.java

@@ -83,6 +83,15 @@ public class ScrapperNPCSettings implements TraitSettings<ScrapperSetting> {
         }
     }
 
+    /**
+     * Gets whether this scrapper is able to split an enchanted book
+     *
+     * @return <p>True if this scrapper is able to split an enchanted book</p>
+     */
+    public boolean splitEnchantedBook() {
+        return asBoolean(ScrapperSetting.SPLIT_ENCHANTED_BOOK);
+    }
+
     /**
      * Gets the raw current value of a setting
      *
@@ -171,6 +180,15 @@ public class ScrapperNPCSettings implements TraitSettings<ScrapperSetting> {
         return asString(ScrapperSetting.COST_MESSAGE_NETHERITE);
     }
 
+    /**
+     * Gets the message to use for displaying enchanted book salvage cost
+     *
+     * @return <p>The message to use for displaying enchanted book salvage cost</p>
+     */
+    public String getEnchantedBookCostMessage() {
+        return asString(ScrapperSetting.COST_MESSAGE_ENCHANTED_BOOK);
+    }
+
     @Override
     @NotNull
     public String getCoolDownUnexpiredMessage() {
@@ -466,4 +484,24 @@ public class ScrapperNPCSettings implements TraitSettings<ScrapperSetting> {
         return asString(ScrapperSetting.CANNOT_SALVAGE_NETHERITE_MESSAGE);
     }
 
+    /**
+     * Gets the message to display when explaining that this scrapper is unable to salvage enchanted books
+     *
+     * @return <p>The message to display when explaining that this scrapper is unable to salvage enchanted books</p>
+     */
+    @NotNull
+    public String getCannotSalvageEnchantedBookMessage() {
+        return asString(ScrapperSetting.CANNOT_SALVAGE_ENCHANTED_BOOK_MESSAGE);
+    }
+
+    /**
+     * Gets the message to display when explaining that the scrapper cannot salvage an enchanted book with a single enchantment
+     *
+     * @return <p>The message to display when explaining that the scrapper cannot salvage an enchanted book with a single enchantment</p>
+     */
+    @NotNull
+    public String getCannotSplitEnchantedBookFurtherMessage() {
+        return asString(ScrapperSetting.CANNOT_SPLIT_ENCHANTED_BOOK_FURTHER_MESSAGE);
+    }
+
 }

src/main/java/net/knarcraft/blacksmith/config/scrapper/ScrapperSetting.java

@@ -91,6 +91,12 @@ public enum ScrapperSetting implements Setting {
      */
     SALVAGE_NETHERITE("salvageNetherite", SettingValueType.BOOLEAN, true,
             "Whether to enable salvaging of netherite items", true, false),
+
+    /**
+     * The setting for whether the NPC should allow salvaging an enchanted books with several enchantments into several books with one enchantment
+     */
+    SPLIT_ENCHANTED_BOOK("splitEnchantedBook", SettingValueType.BOOLEAN, false, "Whether to enable " +
+            "splitting of enchanted books", true, false),
     
     /*-----------
      | Messages |
@@ -194,6 +200,13 @@ public enum ScrapperSetting implements Setting {
             "&eIt will cost &a{cost}&e to salvage that &a{item}&e into diamond!",
             "The message to display when explaining the shown item's netherite salvage cost", true, true),
 
+    /**
+     * The message displayed when displaying the cost of salvaging the player's held enchanted book
+     */
+    COST_MESSAGE_ENCHANTED_BOOK("costMessageEnchantedBook", SettingValueType.STRING,
+            "&eIt will cost &a{cost}&e to salvage that enchanted book!",
+            "The message to display when explaining the shown enchanted book's salvage cost", true, true),
+
     /**
      * The message displayed when explaining that all items will be returned as salvage
      */
@@ -236,6 +249,20 @@ public enum ScrapperSetting implements Setting {
             "&cI'm sorry, but I'm unable to salvage netherite items!",
             "The message to display when asked to salvage netherite items, and that option is disabled", true, true),
 
+    /**
+     * The message displayed when explaining that enchanted book salvage is disabled
+     */
+    CANNOT_SALVAGE_ENCHANTED_BOOK_MESSAGE("cannotSalvageEnchantedBookMessage", SettingValueType.STRING,
+            "&cI'm sorry, but I'm unable to salvage enchanted books!",
+            "The message to display when asked to salvage enchanted books, and the option is disabled", true, true),
+
+    /**
+     * The message displayed when explaining that a player cannot salvage an enchanted book containing a single enchantment
+     */
+    CANNOT_SPLIT_ENCHANTED_BOOK_FURTHER_MESSAGE("cannotSplitEnchantedBookFurtherMessage", SettingValueType.STRING,
+            "&cI'm sorry, but I cannot salvage that enchanted book any further",
+            "The message displayed when a player attempts to  salvage an enchanted book with a single enchantment", true, true),
+
     /**
      * The message displayed when clicking a scrapper with an empty hand
      */
@@ -249,21 +276,47 @@ public enum ScrapperSetting implements Setting {
     /**
      * The setting for the salvage cost
      */
-    SALVAGE_COST("salvagePrice", SettingValueType.POSITIVE_DOUBLE, 0,
+    SALVAGE_COST("salvagePrice", SettingValueType.ADVANCED_COST, 0,
             "The cost of using a scrapper to salvage an item", false, false),
 
     /**
      * The setting for the armor trim salvage cost
      */
-    ARMOR_TRIM_SALVAGE_COST("armorTrimSalvagePrice", SettingValueType.POSITIVE_DOUBLE, 5,
+    ARMOR_TRIM_SALVAGE_COST("armorTrimSalvagePrice", SettingValueType.ADVANCED_COST, 5,
             "The cost of using the scrapper to remove armor trim", false, false),
 
     /**
      * The setting for the netherite salvage cost
      */
-    NETHERITE_SALVAGE_COST("netheriteSalvagePrice", SettingValueType.POSITIVE_DOUBLE, 15,
+    NETHERITE_SALVAGE_COST("netheriteSalvagePrice", SettingValueType.ADVANCED_COST, 15,
             "The cost of using the scrapper to remove netherite from an item", false, false),
 
+    /**
+     * The setting for the enchanted book salvage cost
+     */
+    ENCHANTED_BOOK_SALVAGE_COST("enchantedBookSalvagePrice", SettingValueType.ADVANCED_COST, 15,
+            "The cost of using the scrapper to split an enchanted book", false, false),
+
+    /**
+     * The setting for whether to multiply enchanted book salvage cost
+     */
+    MULTIPLY_ENCHANTED_BOOK_SALVAGE_COST("multiplyEnchantedBookSalvageCost", SettingValueType.BOOLEAN, false,
+            "Whether to multiply the enchanted book salvage cost with the number of enchantments", false, false),
+
+    /**
+     * The mathematical formula for increasing salvage cost
+     */
+    SALVAGE_COST_INCREASE("salvageCostIncrease", SettingValueType.STRING, "{cost}*{timesUsed}",
+            "The mathematical formula for salvage cost increase when continually used within the same hour. " +
+                    "This is necessary for some servers where items can be easily farmed. Set to {cost} to disable behavior.", false, false),
+
+    /**
+     * The mathematical formula for increasing salvage cooldown
+     */
+    SALVAGE_COOLDOWN_INCREASE("salvageCooldownIncrease", SettingValueType.STRING, "{cooldown}*{timesUsed}",
+            "The mathematical formula for salvage cooldown increase when continually used within the same hour. " +
+                    "This is necessary for some servers where items can be easily farmed. Set to {cooldown} to disable behavior.", false, false),
+
     /**
      * Whether to display exact time in minutes and seconds when displaying a remaining cool-down
      */

src/main/java/net/knarcraft/blacksmith/container/ActionCost.java

@@ -0,0 +1,274 @@
+package net.knarcraft.blacksmith.container;
+
+import net.knarcraft.blacksmith.BlacksmithPlugin;
+import net.knarcraft.blacksmith.manager.EconomyManager;
+import net.md_5.bungee.api.ChatColor;
+import org.bukkit.NamespacedKey;
+import org.bukkit.configuration.serialization.ConfigurationSerializable;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.meta.ItemMeta;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+
+/**
+ * The cost of performing an action
+ *
+ * @param monetaryCost        <p>The monetary cost of the action</p>
+ * @param expCost             <p>The experience cost of the action</p>
+ * @param itemCost            <p>The item-based cost of the action</p>
+ * @param requiredPermissions <p>The permission required for the action</p>
+ */
+public record ActionCost(double monetaryCost, int expCost, @Nullable ItemStack itemCost,
+                         @NotNull Set<String> requiredPermissions) implements ConfigurationSerializable {
+
+    /**
+     * Instantiates a new empty action cost
+     */
+    public ActionCost() {
+        this(0, 0, null, Set.of());
+    }
+
+    /**
+     * Instantiates a new action cost with the specified monetary cost
+     *
+     * @param monetaryCost <p>The monetary cost to set</p>
+     */
+    public ActionCost(double monetaryCost) {
+        this(monetaryCost, 0, null, Set.of());
+    }
+
+    /**
+     * Changes the monetary cost of this action
+     *
+     * @param monetaryCost <p>The new monetary cost</p>
+     * @return <p>The resulting action cost</p>
+     */
+    public ActionCost changeMonetaryCost(double monetaryCost) {
+        return new ActionCost(monetaryCost, this.expCost, this.itemCost, this.requiredPermissions);
+    }
+
+    /**
+     * Changes the experience cost of this action
+     *
+     * @param expCost <p>The new experience cost</p>
+     * @return <p>The resulting action cost</p>
+     */
+    public ActionCost changeExpCost(int expCost) {
+        return new ActionCost(this.monetaryCost, expCost, this.itemCost, this.requiredPermissions);
+    }
+
+    /**
+     * Changes the item cost of this action
+     *
+     * @param itemCost <p>The new item cost</p>
+     * @return <p>The resulting action cost</p>
+     */
+    public ActionCost changeItemCost(@Nullable ItemStack itemCost) {
+        return new ActionCost(this.monetaryCost, this.expCost, itemCost, this.requiredPermissions);
+    }
+
+    /**
+     * Changes the permission cost of this action
+     *
+     * @param requiredPermissions <p>The new permission cost</p>
+     * @return <p>The resulting action cost</p>
+     */
+    public ActionCost changePermissionCost(@NotNull Set<String> requiredPermissions) {
+        return new ActionCost(this.monetaryCost, this.expCost, this.itemCost, requiredPermissions);
+    }
+
+    /**
+     * Gets this action cost's costs as a string
+     *
+     * @param player <p>The player to calculate the cost for</p>
+     * @return <p>The string representation of this action cost</p>
+     */
+    @NotNull
+    public String getCostString(@NotNull Player player) {
+        StringBuilder builder = new StringBuilder();
+        if (monetaryCost > 0) {
+            builder.append(EconomyManager.format(monetaryCost)).append(", ").append("\n");
+        }
+        if (expCost > 0) {
+            builder.append(expCost).append("exp, ").append("\n");
+        }
+        if (itemCost != null) {
+            NamespacedKey itemName = itemCost.getType().getKeyOrNull();
+            if (itemName != null) {
+                builder.append(itemCost.getAmount()).append(" x ").append(itemName);
+                ItemMeta itemMeta = itemCost.getItemMeta();
+                if (itemMeta != null && itemMeta.hasDisplayName()) {
+                    builder.append("(").append(itemMeta.getDisplayName()).append(")");
+                }
+                if (itemMeta != null && itemMeta.hasLore() && itemMeta.getLore() != null) {
+                    for (String lore : itemMeta.getLore()) {
+                        builder.append("\n").append(lore);
+                    }
+                }
+                builder.append("\n");
+            }
+        }
+        if (!requiredPermissions().isEmpty()) {
+            for (String permission : requiredPermissions()) {
+                if (player.hasPermission(permission)) {
+                    builder.append(ChatColor.DARK_GREEN).append("O ").append(permission).append("\n");
+                } else {
+                    builder.append(ChatColor.DARK_RED).append("X ").append(permission).append("\n");
+                }
+            }
+        }
+        return builder.toString();
+    }
+
+    /**
+     * Checks whether the given player is able to pay this action cost
+     *
+     * @param player <p>The player to check</p>
+     * @return <p>True if the player is able to pay</p>
+     */
+    public boolean canPay(@NotNull Player player) {
+        for (String permission : this.requiredPermissions) {
+            if (!player.hasPermission(permission)) {
+                return false;
+            }
+        }
+
+        if (player.getExp() < this.expCost || !EconomyManager.hasEnough(player, this.monetaryCost)) {
+            return false;
+        }
+
+        return hasEnoughValidItemsInInventory(player);
+    }
+
+    /**
+     * Takes exp, money and items from the player, according to this cost
+     *
+     * @param player <p>The player to take the payment from</p>
+     */
+    public void takePayment(@NotNull Player player) {
+        player.giveExp(-expCost);
+        EconomyManager.withdraw(player, monetaryCost);
+        takeItemCost(player);
+    }
+
+    /**
+     * Checks whether the given player has enough items specified as the item cost
+     *
+     * @param player <p>The player to check</p>
+     * @return <p>True if the player has enough items in their inventory</p>
+     */
+    private boolean hasEnoughValidItemsInInventory(@NotNull Player player) {
+        if (this.itemCost == null) {
+            return true;
+        }
+
+        int amountInInventory = 0;
+        for (Map.Entry<Integer, Integer> entry : getValidItems(player).entrySet()) {
+            amountInInventory += entry.getValue();
+        }
+        return this.itemCost.getAmount() >= amountInInventory;
+    }
+
+    /**
+     * Gets all items in a player's inventory equal to the specified item
+     *
+     * @param player <p>The player to get valid items for</p>
+     * @return <p>All valid items in the format: Inventory id -> Amount</p>
+     */
+    @NotNull
+    private Map<Integer, Integer> getValidItems(@NotNull Player player) {
+        if (this.itemCost == null) {
+            return new HashMap<>();
+        }
+
+        ItemMeta targetMeta = this.itemCost.getItemMeta();
+        String displayName = null;
+        List<String> lore = null;
+        if (targetMeta != null) {
+            displayName = targetMeta.hasDisplayName() ? targetMeta.getDisplayName() : null;
+            lore = targetMeta.hasLore() ? targetMeta.getLore() : null;
+        }
+
+        Map<Integer, Integer> output = new HashMap<>();
+        for (Map.Entry<Integer, ? extends ItemStack> entry : player.getInventory().all(this.itemCost.getType()).entrySet()) {
+            if (targetMeta != null) {
+                // Only consider item if the name and lore is the same
+                ItemMeta meta = entry.getValue().getItemMeta();
+                if (meta == null || (displayName != null && (!meta.hasDisplayName() ||
+                        !meta.getDisplayName().equals(displayName)) || lore != null && (!meta.hasLore() ||
+                        meta.getLore() == null || !meta.getLore().equals(lore)))) {
+                    continue;
+                }
+            }
+            output.put(entry.getKey(), entry.getValue().getAmount());
+        }
+
+        return output;
+    }
+
+    /**
+     * Takes the amount of items specified as the cost for this action
+     *
+     * @param player <p>The player to take the items from</p>
+     */
+    private void takeItemCost(@NotNull Player player) {
+        if (this.itemCost == null) {
+            return;
+        }
+
+        int clearedAmount = 0;
+        for (Map.Entry<Integer, Integer> entry : getValidItems(player).entrySet()) {
+            int amount = entry.getValue();
+            if (amount <= this.itemCost.getAmount() - clearedAmount) {
+                clearedAmount += amount;
+                player.getInventory().clear(entry.getKey());
+            } else {
+                clearedAmount = this.itemCost.getAmount();
+                ItemStack item = player.getInventory().getItem(entry.getKey());
+                if (item != null) {
+                    item.setAmount(amount - clearedAmount);
+                } else {
+                    BlacksmithPlugin.error("An item changed after calculating item cost. Was unable to take " +
+                            amount + " items");
+                }
+            }
+
+            if (clearedAmount >= this.itemCost.getAmount()) {
+                break;
+            }
+        }
+    }
+
+    /**
+     * Deserializes an action cost
+     *
+     * @param serialized <p>The serialized action cost</p>
+     * @return <p>The deserialized action cost</p>
+     */
+    @SuppressWarnings({"unused", "unchecked"})
+    public static ActionCost deserialize(Map<String, Object> serialized) {
+        double monetaryCost = (double) serialized.get("monetaryCost");
+        int expCost = (int) serialized.get("expCost");
+        ItemStack itemCost = (ItemStack) serialized.get("itemCost");
+        Set<String> requiredPermissions = (Set<String>) serialized.get("requiredPermissions");
+        return new ActionCost(monetaryCost, expCost, itemCost, requiredPermissions);
+    }
+
+    @Override
+    public @NotNull Map<String, Object> serialize() {
+        Map<String, Object> serialized = new HashMap<>();
+        serialized.put("monetaryCost", Optional.of(this.monetaryCost));
+        serialized.put("expCost", Optional.of(this.expCost));
+        serialized.put("itemCost", itemCost);
+        serialized.put("requiredPermissions", this.requiredPermissions);
+        return serialized;
+    }
+
+}

src/main/java/net/knarcraft/blacksmith/formatting/ItemType.java

@@ -15,10 +15,10 @@ public enum ItemType {
      *
      * @return <p>The name of this item type</p>
      */
-    public String getItemTypeName() {
+    public FormatBuilder getItemTypeName() {
         return switch (this) {
-            case MATERIAL -> new FormatBuilder(Translatable.ITEM_TYPE_MATERIAL).toString();
-            case ENCHANTMENT -> new FormatBuilder(Translatable.ITEM_TYPE_ENCHANTMENT).toString();
+            case MATERIAL -> new FormatBuilder(Translatable.ITEM_TYPE_MATERIAL);
+            case ENCHANTMENT -> new FormatBuilder(Translatable.ITEM_TYPE_ENCHANTMENT);
         };
     }
 

src/main/java/net/knarcraft/blacksmith/formatting/NPCFormatter.java

@@ -22,8 +22,8 @@ public final class NPCFormatter {
      * @param message <p>The message to send</p>
      */
     public static void sendNPCMessage(@NotNull NPC npc, @NotNull Player player, @NotNull String message) {
-        player.sendMessage(new FormatBuilder(Translatable.NPC_TALK_FORMAT).replace("{npc}",
-                npc.getName()).replace("{message}", message).color().toString());
+        new FormatBuilder(Translatable.NPC_TALK_FORMAT).replace("{npc}",
+                npc.getName()).replace("{message}", message).displayColored(player);
     }
 
     /**

src/main/java/net/knarcraft/blacksmith/formatting/Translatable.java

@@ -140,7 +140,12 @@ public enum Translatable implements TranslatableMessage {
     /**
      * The format to use for formatting any message spoken by a blacksmith NPC
      */
-    NPC_TALK_FORMAT;
+    NPC_TALK_FORMAT,
+
+    /**
+     * The text to display when explaining that a cost must be a positive double
+     */
+    DOUBLE_COST_REQUIRED;
 
     /**
      * Gets the message to display when displaying the raw value of messages
@@ -150,7 +155,7 @@ public enum Translatable implements TranslatableMessage {
      */
     @NotNull
     public static FormatBuilder getRawValueMessage(@NotNull String rawValue) {
-        return new FormatBuilder(Translatable.RAW_VALUE).replace("{rawValue}", rawValue);
+        return new FormatBuilder(Translatable.RAW_VALUE).color().replace("{rawValue}", rawValue);
     }
 
     /**

src/main/java/net/knarcraft/blacksmith/manager/EconomyManager.java

@@ -3,9 +3,14 @@ package net.knarcraft.blacksmith.manager;
 import net.knarcraft.blacksmith.BlacksmithPlugin;
 import net.knarcraft.blacksmith.config.blacksmith.GlobalBlacksmithSettings;
 import net.knarcraft.blacksmith.config.scrapper.GlobalScrapperSettings;
+import net.knarcraft.blacksmith.container.ActionCost;
 import net.knarcraft.blacksmith.property.SalvageMethod;
 import net.knarcraft.blacksmith.util.ItemHelper;
+import net.knarcraft.blacksmith.util.SalvageHelper;
+import net.knarcraft.knarlib.formatting.StringReplacer;
 import net.milkbowl.vault.economy.Economy;
+import net.objecthunter.exp4j.Expression;
+import net.objecthunter.exp4j.ExpressionBuilder;
 import org.bukkit.Material;
 import org.bukkit.enchantments.Enchantment;
 import org.bukkit.entity.Player;
@@ -54,10 +59,12 @@ public class EconomyManager {
      *
      * @param player        <p>The player holding an item</p>
      * @param salvageMethod <p>The salvage method to check</p>
+     * @param item          <p>The item to be salvaged</p>
      * @return <p>Whether the player cannot pay for the salvage</p>
      */
-    public static boolean cannotPayForSalvage(@NotNull Player player, @NotNull SalvageMethod salvageMethod) {
-        return economy.getBalance(player) - getSalvageCost(salvageMethod) < 0;
+    public static boolean cannotPayForSalvage(@NotNull Player player, @NotNull SalvageMethod salvageMethod,
+                                              @NotNull ItemStack item) {
+        return !getSalvageCost(salvageMethod, item, player).canPay(player);
     }
 
     /**
@@ -76,26 +83,63 @@ public class EconomyManager {
      * Gets the human-readable cost of salvaging an item
      *
      * @param salvageMethod <p>The salvage method to get the cost for</p>
+     * @param item          <p>The item to be salvaged</p>
+     * @param player        <p>The player to provide the cost to</p>
      * @return <p>The formatted cost</p>
      */
     @NotNull
-    public static String formatSalvageCost(@NotNull SalvageMethod salvageMethod) {
-        return economy.format(getSalvageCost(salvageMethod));
+    public static String formatSalvageCost(@NotNull SalvageMethod salvageMethod, @NotNull ItemStack item,
+                                           @NotNull Player player) {
+        return getSalvageCost(salvageMethod, item, player).getCostString(player);
+    }
+
+    /**
+     * Gets whether the given player has enough money to pay the given cost
+     *
+     * @param player <p>The player to check</p>
+     * @param cost   <p>The required cost</p>
+     * @return <p>True if the player has enough money to cover the cost</p>
+     */
+    public static boolean hasEnough(@NotNull Player player, double cost) {
+        return economy.getBalance(player) >= cost;
+    }
+
+    /**
+     * Formats a number as an economy cost
+     *
+     * @param cost <p>The cost to format</p>
+     * @return <p>The formatted cost</p>
+     */
+    @NotNull
+    public static String format(double cost) {
+        return economy.format(cost);
     }
 
     /**
      * Gets the cost of salvaging using the specified method
      *
      * @param salvageMethod <p>The salvage method to get cost for</p>
+     * @param item          <p>The item to be salvaged</p>
      * @return <p>The salvage cost</p>
      */
-    private static double getSalvageCost(@NotNull SalvageMethod salvageMethod) {
+    @NotNull
+    private static ActionCost getSalvageCost(@NotNull SalvageMethod salvageMethod, @NotNull ItemStack item,
+                                             @NotNull Player player) {
         GlobalScrapperSettings settings = BlacksmithPlugin.getInstance().getGlobalScrapperSettings();
-        return switch (salvageMethod) {
+        ActionCost cost = switch (salvageMethod) {
             case SALVAGE, EXTENDED_SALVAGE -> settings.getSalvageCost();
             case NETHERITE -> settings.getNetheriteSalvageCost();
             case ARMOR_TRIM -> settings.getArmorTrimSalvageCost();
+            case ENCHANTED_BOOK -> getEnchantedBookSalvageCost(item);
         };
+
+        StringReplacer replacer = new StringReplacer(settings.getSalvageCostIncrease());
+        replacer.add("{cost}", String.valueOf(cost.monetaryCost()));
+        replacer.add("{timesUsed}", String.valueOf(PlayerUsageManager.getUsages(player,
+                System.currentTimeMillis() - 3600000)));
+        Expression expression = new ExpressionBuilder(replacer.replace()).build();
+        cost.changeMonetaryCost(Math.max(cost.monetaryCost(), expression.evaluate()));
+        return cost;
     }
 
     /**
@@ -118,13 +162,30 @@ public class EconomyManager {
      * @param player        <p>The player to withdraw from</p>
      * @param salvageMethod <p>The salvage method to withdraw for</p>
      */
-    public static void withdrawScrapper(@NotNull Player player, @NotNull SalvageMethod salvageMethod) {
-        double cost = getSalvageCost(salvageMethod);
-        if (cost > 0) {
-            economy.withdrawPlayer(player, cost);
+    public static boolean withdrawScrapper(@NotNull Player player, @NotNull SalvageMethod salvageMethod) {
+        ActionCost cost = getSalvageCost(salvageMethod, player.getInventory().getItemInMainHand(), player);
+        if (cost.canPay(player)) {
+            cost.takePayment(player);
+            return true;
+        } else {
+            return false;
         }
     }
 
+    /**
+     * Withdraws money from a player
+     *
+     * @param player       <p>The player to withdraw from</p>
+     * @param monetaryCost <p>The cost to withdraw</p>
+     * @throws IllegalArgumentException <p>If a negative cost is given</p>
+     */
+    public static void withdraw(@NotNull Player player, double monetaryCost) {
+        if (monetaryCost < 0) {
+            throw new IllegalArgumentException("Cannot withdraw a negative amount");
+        }
+        economy.withdrawPlayer(player, monetaryCost);
+    }
+
     /**
      * Gets the cost of the item in the given player's main hand
      *
@@ -183,6 +244,23 @@ public class EconomyManager {
         return price;
     }
 
+    /**
+     * Gets the cost of scrapping an enchanted book
+     *
+     * @param item <p>The enchanted book to calculate cost for</p>
+     * @return <p>The cost of scrapping the enchanted book</p>
+     */
+    @NotNull
+    private static ActionCost getEnchantedBookSalvageCost(@NotNull ItemStack item) {
+        GlobalScrapperSettings settings = BlacksmithPlugin.getInstance().getGlobalScrapperSettings();
+
+        ActionCost cost = settings.getEnchantedBookSalvageCost();
+        if (settings.multiplyEnchantedBokSalvagePrice()) {
+            cost.changeMonetaryCost(cost.monetaryCost() * Math.max(SalvageHelper.getEnchantmentCount(item) - 1, 1));
+        }
+        return cost;
+    }
+
     /**
      * Sets up Vault for economy
      *

src/main/java/net/knarcraft/blacksmith/manager/PlayerUsageManager.java

@@ -0,0 +1,75 @@
+package net.knarcraft.blacksmith.manager;
+
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * A manager for keeping track of players using scrappers
+ */
+public class PlayerUsageManager {
+
+    private static final Map<Player, Set<Long>> playerUsages = new HashMap<>();
+
+    /**
+     * Register that a player has used a scrapper
+     *
+     * @param player <p>The player using a scrapper</p>
+     */
+    public static void registerUsage(@NotNull Player player) {
+        playerUsages.putIfAbsent(player, new HashSet<>());
+        Set<Long> usages = playerUsages.get(player);
+        usages.add(System.currentTimeMillis());
+    }
+
+    /**
+     * Gets how many times the given player has used a scrapper after the given timestamp
+     *
+     * @param player         <p>The player to check usages for</p>
+     * @param afterTimestamp <p>The timestamp of when to start looking for usages</p>
+     * @return <p>The number of scrapper uses for the given player</p>
+     */
+    public static int getUsages(@NotNull Player player, @NotNull Long afterTimestamp) {
+        Set<Long> usages = playerUsages.get(player);
+        if (usages == null) {
+            return 0;
+        }
+
+        int uses = 0;
+        Set<Long> expired = new HashSet<>();
+        for (Long usageTime : usages) {
+            if (usageTime < afterTimestamp) {
+                expired.add(usageTime);
+            } else {
+                uses++;
+            }
+        }
+
+        // Remove expired data
+        usages.removeAll(expired);
+
+        return uses;
+    }
+
+    /**
+     * Removes all expired timestamps
+     *
+     * @param afterTimestamp <p>The timestamp for the earliest time of valid timestamps</p>
+     */
+    public static void removeExpiredData(@NotNull Long afterTimestamp) {
+        for (Set<Long> usageSet : playerUsages.values()) {
+            Set<Long> expired = new HashSet<>();
+            for (Long item : usageSet) {
+                if (item < afterTimestamp) {
+                    expired.add(item);
+                }
+            }
+            usageSet.removeAll(expired);
+        }
+    }
+
+}

src/main/java/net/knarcraft/blacksmith/property/CostModifyAction.java

@@ -0,0 +1,43 @@
+package net.knarcraft.blacksmith.property;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * An action for modifying cost
+ */
+public enum CostModifyAction {
+
+    /**
+     * Adds some cost to the existing cost, effectively modifying the total cost
+     */
+    ADD,
+
+    /**
+     * Clears the cost completely
+     */
+    CLEAR,
+
+    /**
+     * Sets the cost to the new cost, clearing any other existing costs
+     */
+    SET,
+    ;
+
+    /**
+     * Gets the action specified by the given string
+     *
+     * @param input <p>The input string to parse</p>
+     * @return <p>The action, or null if not matched</p>
+     */
+    @Nullable
+    public static CostModifyAction fromString(@NotNull String input) {
+        for (CostModifyAction action : CostModifyAction.values()) {
+            if (input.toUpperCase().equals(action.name())) {
+                return action;
+            }
+        }
+        return null;
+    }
+
+}

src/main/java/net/knarcraft/blacksmith/property/CostType.java

@@ -0,0 +1,49 @@
+package net.knarcraft.blacksmith.property;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * The type of costs applicable to an advanced cost configuration
+ */
+public enum CostType {
+
+    /**
+     * A monetary cost from an economy plugin
+     */
+    ECONOMY,
+
+    /**
+     * A permission requirement, rather than a cost
+     */
+    PERMISSION,
+
+    /**
+     * In-game experience levels
+     */
+    EXP,
+
+    /**
+     * A specific item is consumed
+     */
+    ITEM,
+    ;
+
+    /**
+     * Parses a text string denoting a cost type
+     *
+     * @param input <p>The input to parse</p>
+     * @return <p>The parsed cost type, or null if not matched</p>
+     */
+    @Nullable
+    public static CostType parse(@NotNull String input) {
+        String normalized = input.trim().toUpperCase();
+        for (CostType costType : CostType.values()) {
+            if (normalized.equals(costType.name())) {
+                return costType;
+            }
+        }
+        return null;
+    }
+
+}

src/main/java/net/knarcraft/blacksmith/property/SalvageMethod.java

@@ -25,4 +25,9 @@ public enum SalvageMethod {
      */
     NETHERITE,
 
+    /**
+     * Splitting enchantments of an enchanted book
+     */
+    ENCHANTED_BOOK,
+
 }

src/main/java/net/knarcraft/blacksmith/trait/BlacksmithTrait.java

@@ -80,9 +80,8 @@ public class BlacksmithTrait extends CustomTrait<BlacksmithSetting> {
                 (!reforgeAbleItems.isEmpty() && !reforgeAbleItems.contains(hand.getType()));
 
         if (notHoldingAnvil && notHoldingRepairable) {
-            String invalidMessage = new FormatBuilder(config.getInvalidItemMessage()).replace("{title}",
-                    config.getBlacksmithTitle()).toString();
-            NPCFormatter.sendNPCMessage(this.npc, player, invalidMessage);
+            NPCFormatter.sendNPCMessage(this.npc, player, new FormatBuilder(config.getInvalidItemMessage()).
+                    replace("{title}", config.getBlacksmithTitle()));
             return;
         }
 

src/main/java/net/knarcraft/blacksmith/trait/CustomTrait.java

@@ -187,12 +187,14 @@ public abstract class CustomTrait<K extends Setting> extends Trait {
         if (isBlacksmith) {
             EconomyManager.withdrawBlacksmith(player);
         } else if (this.session instanceof SalvageSession salvageSession) {
-            EconomyManager.withdrawScrapper(player, salvageSession.salvageMethod);
-        }
+            if (!EconomyManager.withdrawScrapper(player, salvageSession.salvageMethod)) {
+                return;
+            }
 
-        session.scheduleAction();
+        }
         PlayerInventory playerInventory = player.getInventory();
         ItemStack heldItem = player.getInventory().getItemInMainHand();
+        session.scheduleAction();
 
         //Display the item in the NPC's hand
         Entity entity = npc.getEntity();

src/main/java/net/knarcraft/blacksmith/trait/ReforgeSession.java

@@ -59,6 +59,8 @@ public class ReforgeSession extends Session implements Runnable {
 
             enchantments = new ArrayList<>();
             for (Enchantment enchantment : enchantmentRegistry) {
+                // Note: While depreciated in Spigot, the new method is not available for Paper
+                //noinspection deprecation
                 enchantments.add(enchantment.getKey().getKey());
             }
         }

src/main/java/net/knarcraft/blacksmith/trait/SalvageSession.java

@@ -7,9 +7,13 @@ import net.knarcraft.blacksmith.event.ScrapperSalvageFailEvent;
 import net.knarcraft.blacksmith.event.ScrapperSalvageSucceedEvent;
 import net.knarcraft.blacksmith.formatting.NPCFormatter;
 import net.knarcraft.blacksmith.manager.EconomyManager;
+import net.knarcraft.blacksmith.manager.PlayerUsageManager;
 import net.knarcraft.blacksmith.property.SalvageMethod;
 import net.knarcraft.blacksmith.util.ItemHelper;
 import net.knarcraft.blacksmith.util.SalvageHelper;
+import net.knarcraft.knarlib.formatting.StringReplacer;
+import net.objecthunter.exp4j.Expression;
+import net.objecthunter.exp4j.ExpressionBuilder;
 import org.bukkit.Material;
 import org.bukkit.Sound;
 import org.bukkit.entity.LivingEntity;
@@ -69,7 +73,7 @@ public class SalvageSession extends Session implements Runnable {
             return true;
         }
 
-        if (EconomyManager.cannotPayForSalvage(this.player, this.salvageMethod)) {
+        if (EconomyManager.cannotPayForSalvage(this.player, this.salvageMethod, this.itemToSalvage)) {
             NPCFormatter.sendNPCMessage(this.npc, this.player, this.config.getInsufficientFundsMessage());
             return true;
         }
@@ -93,6 +97,7 @@ public class SalvageSession extends Session implements Runnable {
             case EXTENDED_SALVAGE -> Material.CRAFTING_TABLE;
             case SALVAGE -> Material.ANVIL;
             case NETHERITE, ARMOR_TRIM -> Material.SMITHING_TABLE;
+            case ENCHANTED_BOOK -> Material.ENCHANTING_TABLE;
         };
     }
 
@@ -120,8 +125,14 @@ public class SalvageSession extends Session implements Runnable {
 
         // Start cool-down
         Calendar wait = Calendar.getInstance();
-        wait.add(Calendar.SECOND, this.config.getSalvageCoolDown());
+        StringReplacer replacer = new StringReplacer(BlacksmithPlugin.getInstance().getGlobalScrapperSettings().getSalvageCooldownIncrease());
+        replacer.add("{cooldown}", String.valueOf(this.config.getSalvageCoolDown()));
+        replacer.add("{timesUsed}", String.valueOf(PlayerUsageManager.getUsages(player, System.currentTimeMillis() - 3600000)));
+        Expression expression = new ExpressionBuilder(replacer.replace()).build();
+
+        wait.add(Calendar.SECOND, Math.max((int) expression.evaluate(), this.config.getSalvageCoolDown()));
         this.scrapperTrait.addCoolDown(this.player.getUniqueId(), wait);
+        PlayerUsageManager.registerUsage(this.player);
     }
 
     /**

src/main/java/net/knarcraft/blacksmith/trait/ScrapperTrait.java

@@ -21,6 +21,7 @@ import org.bukkit.Material;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.ArmorMeta;
+import org.bukkit.inventory.meta.EnchantmentStorageMeta;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -116,7 +117,7 @@ public class ScrapperTrait extends CustomTrait<ScrapperSetting> {
             return;
         }
         // Print the cost to the player
-        printCostMessage(player, itemInHand, EconomyManager.formatSalvageCost(result.salvageMethod()),
+        printCostMessage(player, itemInHand, EconomyManager.formatSalvageCost(result.salvageMethod(), itemInHand, player),
                 result.salvageMethod());
     }
 
@@ -144,6 +145,13 @@ public class ScrapperTrait extends CustomTrait<ScrapperSetting> {
             return result;
         }
 
+        result = isEnchantedBookSalvage(player, itemInHand);
+        if (result.salvageState() == SalvageState.NO_SALVAGE) {
+            return null;
+        } else if (result.salvageState() == SalvageState.FOUND_SALVAGE) {
+            return result;
+        }
+
         result = isNormalSalvage(player, itemInHand, extended);
         if (result.salvageState() == SalvageState.NO_SALVAGE) {
             return null;
@@ -173,7 +181,7 @@ public class ScrapperTrait extends CustomTrait<ScrapperSetting> {
             return new SalvageResult(SalvageMethod.SALVAGE, new ArrayList<>(), SalvageState.NO_SALVAGE, 0);
         }
 
-        // Check if the item is enchanted, and whether this blacksmith can salvage it
+        // Check if the item is enchanted, and whether this scrapper can salvage it
         if (!itemInHand.getEnchantments().isEmpty() && !getSettings().salvageEnchanted()) {
             NPCFormatter.sendNPCMessage(this.npc, player, getSettings().getCannotSalvageEnchantedMessage());
             return new SalvageResult(SalvageMethod.SALVAGE, new ArrayList<>(), SalvageState.NO_SALVAGE, 0);
@@ -192,6 +200,37 @@ public class ScrapperTrait extends CustomTrait<ScrapperSetting> {
         }
     }
 
+    /**
+     * Gets the result of trying to salvage the item as an enchanted book
+     *
+     * @param player     <p>The player trying to salvage the item</p>
+     * @param itemInHand <p>The item to be salvaged</p>
+     * @return <p>The result of attempting the salvage</p>
+     */
+    private SalvageResult isEnchantedBookSalvage(@NotNull Player player, @NotNull ItemStack itemInHand) {
+        if (itemInHand.getType() != Material.ENCHANTED_BOOK ||
+                !(itemInHand.getItemMeta() instanceof EnchantmentStorageMeta)) {
+            return new SalvageResult(SalvageMethod.ENCHANTED_BOOK, new ArrayList<>(), SalvageState.INCORRECT_METHOD, 0);
+        }
+
+        if (!getSettings().splitEnchantedBook()) {
+            NPCFormatter.sendNPCMessage(this.npc, player, getSettings().getCannotSalvageEnchantedBookMessage());
+            return new SalvageResult(SalvageMethod.ENCHANTED_BOOK, new ArrayList<>(), SalvageState.NO_SALVAGE, 0);
+        }
+
+        if (SalvageHelper.getEnchantmentCount(itemInHand) <= 1) {
+            NPCFormatter.sendNPCMessage(this.npc, player, getSettings().getCannotSplitEnchantedBookFurtherMessage());
+            return new SalvageResult(SalvageMethod.ENCHANTED_BOOK, new ArrayList<>(), SalvageState.NO_SALVAGE, 0);
+        }
+
+        List<ItemStack> salvage = SalvageHelper.getEnchantedBookSalvage(itemInHand);
+        boolean noUsefulSalvage = salvage == null || salvage.isEmpty();
+        if (noUsefulSalvage) {
+            return new SalvageResult(SalvageMethod.ENCHANTED_BOOK, new ArrayList<>(), SalvageState.NO_SALVAGE, 0);
+        }
+        return new SalvageResult(SalvageMethod.ENCHANTED_BOOK, salvage, SalvageState.FOUND_SALVAGE, 1);
+    }
+
     /**
      * Gets the result of trying to salvage the item as a netherite applied item
      *
@@ -271,6 +310,8 @@ public class ScrapperTrait extends CustomTrait<ScrapperSetting> {
             NPCFormatter.sendNPCMessage(this.npc, player, replacer.replace(getSettings().getCostMessage()));
         } else if (salvageMethod == SalvageMethod.NETHERITE) {
             NPCFormatter.sendNPCMessage(this.npc, player, replacer.replace(getSettings().getNetheriteCostMessage()));
+        } else if (salvageMethod == SalvageMethod.ENCHANTED_BOOK) {
+            NPCFormatter.sendNPCMessage(this.npc, player, replacer.replace(getSettings().getEnchantedBookCostMessage()));
         } else {
             BlacksmithPlugin.error("Unrecognized salvage method " + salvageMethod);
         }
@@ -290,8 +331,8 @@ public class ScrapperTrait extends CustomTrait<ScrapperSetting> {
      * @return <p>True if the item can be theoretically salvaged</p>
      */
     private boolean canBeSalvaged(@NotNull ItemStack item, @NotNull List<Material> salvageAbleItems, boolean extended) {
-        return (extended || ItemHelper.isRepairable(item)) &&
-                (salvageAbleItems.isEmpty() || salvageAbleItems.contains(item.getType()));
+        return item.getType() == Material.ENCHANTED_BOOK || ((extended || ItemHelper.isRepairable(item)) &&
+                (salvageAbleItems.isEmpty() || salvageAbleItems.contains(item.getType())));
     }
 
     /**

src/main/java/net/knarcraft/blacksmith/util/ConfigCommandHelper.java

@@ -5,7 +5,6 @@ import net.knarcraft.blacksmith.config.SettingValueType;
 import net.knarcraft.blacksmith.config.Settings;
 import net.knarcraft.blacksmith.formatting.Translatable;
 import net.knarcraft.knarlib.formatting.FormatBuilder;
-import net.md_5.bungee.api.ChatColor;
 import org.bukkit.command.CommandSender;
 import org.jetbrains.annotations.NotNull;
 
@@ -27,19 +26,20 @@ public final class ConfigCommandHelper {
     /**
      * Changes the value of the setting defined in the user's input
      *
-     * @param args            <p>The arguments given by the user</p>
+     * @param arguments       <p>The arguments given by the user</p>
      * @param detectedSetting <p>The setting recognized from the input, if any</p>
      * @param settings        <p>The global settings object to get settings from</p>
      * @param sender          <p>The command sender to display any output to</p>
      */
-    public static <K extends Setting> void changeValue(@NotNull String[] args,
+    public static <K extends Setting> void changeValue(@NotNull String[] arguments,
                                                        @NotNull K detectedSetting,
                                                        @NotNull Settings<K> settings,
                                                        @NotNull CommandSender sender) {
-        String newValue = args[1];
+        // TODO: Account for action cost
+        String newValue = arguments[1];
         //This makes sure all arguments are treated as a sentence
         if (detectedSetting.getValueType() == SettingValueType.STRING) {
-            newValue = String.join(" ", Arrays.asList(args).subList(1, args.length));
+            newValue = String.join(" ", Arrays.asList(arguments).subList(1, arguments.length));
         }
         settings.changeValue(detectedSetting, newValue);
         getValueChangedMessage(detectedSetting.getCommandName(), newValue).success(sender);
@@ -77,7 +77,7 @@ public final class ConfigCommandHelper {
 
         // Display the current value of the setting
         getCurrentValueMessage(setting.getCommandName(), currentValue).neutral(sender);
-        if (printRawValue) {
+        if (!currentValue.equals(defaultValue) && printRawValue) {
             displayRaw(sender, currentValue);
         }
     }
@@ -89,7 +89,7 @@ public final class ConfigCommandHelper {
      * @param value  <p>The value to display raw</p>
      */
     public static void displayRaw(@NotNull CommandSender sender, @NotNull String value) {
-        sender.sendMessage(Translatable.getRawValueMessage(value.replace(ChatColor.COLOR_CHAR, '&')).toString());
+        new FormatBuilder(Translatable.RAW_VALUE).color().replace("{rawValue}", value).displayRaw(sender);
     }
 
 }

src/main/java/net/knarcraft/blacksmith/util/CostHelper.java

@@ -0,0 +1,215 @@
+package net.knarcraft.blacksmith.util;
+
+import net.knarcraft.blacksmith.container.ActionCost;
+import net.knarcraft.blacksmith.formatting.Translatable;
+import net.knarcraft.blacksmith.property.CostModifyAction;
+import net.knarcraft.blacksmith.property.CostType;
+import net.knarcraft.knarlib.formatting.FormatBuilder;
+import net.knarcraft.knarlib.util.TabCompletionHelper;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * A helper class for setting action costs
+ */
+public final class CostHelper {
+
+    private CostHelper() {
+
+    }
+
+    /**
+     * Parses a simple double cost
+     *
+     * @param commandSender <p>The command sender to notify of any problems</p>
+     * @param costString    <p>The string to parse into a cost</p>
+     * @return <p>The parsed cost, or null if not a valid number</p>
+     */
+    @Nullable
+    public static Double parseSimpleCost(@NotNull CommandSender commandSender,
+                                         @NotNull String costString) throws IllegalArgumentException {
+        try {
+            double cost = Double.parseDouble(costString);
+            if (cost < 0) {
+                throw new NumberFormatException();
+            }
+            return cost;
+        } catch (NumberFormatException exception) {
+            new FormatBuilder(Translatable.DOUBLE_COST_REQUIRED).error(commandSender);
+            return null;
+        }
+    }
+
+    /**
+     * Shows tab-completion actions for altering a cost
+     *
+     * @param arguments <p>The arguments given by the user</p>
+     * @return <p>The available tab-complete options</p>
+     */
+    public static @Nullable List<String> tabCompleteCost(@NotNull String[] arguments) {
+        if (arguments.length == 1) {
+            return List.of("simple", "advanced");
+        } else if (arguments.length == 2) {
+            if (arguments[0].equalsIgnoreCase("simple")) {
+                return List.of();
+            } else {
+                return TabCompletionHelper.filterMatchingStartsWith(TabCompletionHelper.getEnumList(CostModifyAction.class), arguments[1]);
+            }
+        } else if (arguments.length == 3) {
+            if (arguments[0].equalsIgnoreCase("simple")) {
+                return List.of();
+            } else {
+                return TabCompletionHelper.filterMatchingStartsWith(TabCompletionHelper.getEnumList(CostType.class), arguments[2]);
+            }
+        } else if (arguments.length == 4) {
+            CostType costType = CostType.parse(arguments[2]);
+            if (costType == null) {
+                return null;
+            }
+            return switch (costType) {
+                case PERMISSION -> TabCompletionHelper.tabCompletePermission(arguments[3]);
+                case ECONOMY -> List.of("0.5", "1", "10");
+                case EXP -> List.of("1, 5, 10");
+                case ITEM -> List.of();
+            };
+        }
+        return List.of();
+    }
+
+    /**
+     * Modifies the cost of an action
+     *
+     * @param costAction   <p>The action to perform on the cost</p>
+     * @param costTypeName <p>The name of the cost to modify, or null if clearing costs</p>
+     * @param costValue    <p>The value of the new cost, or null if clearing costs</p>
+     * @param oldCost      <p>The previous cost of the action</p>
+     * @param player       <p>The player attempting to alter the action cost</p>
+     * @return <p>The modified action cost, or null if something went wrong</p>
+     */
+    @Nullable
+    public static ActionCost modifyActionCost(@NotNull String costAction, @Nullable String costTypeName,
+                                              @Nullable String costValue, @NotNull ActionCost oldCost,
+                                              @NotNull Player player) {
+        CostType costType;
+        if (costTypeName != null) {
+            costType = CostType.parse(costTypeName);
+        } else {
+            costType = null;
+        }
+
+        CostModifyAction action = CostModifyAction.fromString(costAction);
+        if (action == null) {
+            return null;
+        }
+
+        if (action != CostModifyAction.CLEAR && (costType == null || costValue == null)) {
+            player.sendMessage("Invalid cost type or value specified!");
+            return null;
+        }
+
+        return switch (action) {
+            case CLEAR -> clearActionCost(costType, oldCost);
+            case ADD -> addActionCost(costType, costValue, oldCost, player);
+            case SET -> setActionCost(costType, costValue, player);
+        };
+    }
+
+    /**
+     * Sets the cost to the specified value
+     *
+     * @param costType  <p>The type of cost to set</p>
+     * @param costValue <p>The value of the new cost</p>
+     * @param player    <p>The player to alert if the cost cannot be properly set</p>
+     * @return <p>The new action cost</p>
+     */
+    public static ActionCost setActionCost(@NotNull CostType costType, @NotNull String costValue,
+                                           @NotNull Player player) {
+        return parseCost(costType, costValue, new ActionCost(), player);
+    }
+
+    /**
+     * Modifies a value for the specified action cost
+     *
+     * @param costType  <p>The type of cost to modify</p>
+     * @param costValue <p>The new value of the cost</p>
+     * @param oldCost   <p>The cost to modify</p>
+     * @param player    <p>The player to alert if the cost cannot be properly set</p>
+     * @return <p>The new action cost</p>
+     */
+    public static ActionCost addActionCost(@NotNull CostType costType, @NotNull String costValue,
+                                           @NotNull ActionCost oldCost, @NotNull Player player) {
+        return parseCost(costType, costValue, oldCost, player);
+    }
+
+    /**
+     * Clears an action cost
+     *
+     * @param costType <p>The type of action cost to clear, or null if clearing all action costs</p>
+     * @param oldCost  <p>The old cost to modify, or null if clearing all action costs</p>
+     * @return <p>The modified cost</p>
+     */
+    public static ActionCost clearActionCost(@Nullable CostType costType, @Nullable ActionCost oldCost) {
+        // Clears one or all fields of a cost
+        if (costType == null || oldCost == null) {
+            return new ActionCost();
+        } else {
+            return switch (costType) {
+                case EXP -> oldCost.changeExpCost(0);
+                case ITEM -> oldCost.changeItemCost(null);
+                case ECONOMY -> oldCost.changeMonetaryCost(0);
+                case PERMISSION -> oldCost.changePermissionCost(Set.of());
+            };
+        }
+    }
+
+    /**
+     * Parses an advanced action cost
+     *
+     * @param costType <p>The type of cost to parse</p>
+     * @param value    <p>The value to parse</p>
+     * @param oldCost  <p>The old cost to modify</p>
+     * @param player   <p>The player changing the value</p>
+     * @return <p>The new action cost, or null if the process failed.</p>
+     */
+    @Nullable
+    private static ActionCost parseCost(@NotNull CostType costType, @NotNull String value, @NotNull ActionCost oldCost,
+                                        @NotNull Player player) {
+        switch (costType) {
+            case ECONOMY:
+                double economyCost = Double.parseDouble(value);
+                if (economyCost < 0) {
+                    new FormatBuilder("Cost cannot be negative!").error(player);
+                    return null;
+                }
+                return oldCost.changeMonetaryCost(economyCost);
+            case ITEM:
+                ItemStack itemCost = player.getInventory().getItemInMainHand();
+                if (itemCost.getType().isAir()) {
+                    new FormatBuilder("You have no item in your main hand").error(player);
+                    return null;
+                }
+                return oldCost.changeItemCost(itemCost);
+            case PERMISSION:
+                Set<String> permissionSet = new HashSet<>(Arrays.asList(value.split(",")));
+                return oldCost.changePermissionCost(permissionSet);
+            case EXP:
+                int expCost = Integer.parseInt(value);
+                if (expCost < 0) {
+                    new FormatBuilder("Exp cost cannot be negative!").error(player);
+                    return null;
+                }
+                return oldCost.changeExpCost(expCost);
+            default:
+                return null;
+        }
+    }
+
+}

src/main/java/net/knarcraft/blacksmith/util/SalvageHelper.java

@@ -2,6 +2,7 @@ package net.knarcraft.blacksmith.util;
 
 import net.knarcraft.blacksmith.BlacksmithPlugin;
 import net.knarcraft.blacksmith.container.RecipeResult;
+import org.bukkit.Bukkit;
 import org.bukkit.Material;
 import org.bukkit.Server;
 import org.bukkit.enchantments.Enchantment;
@@ -10,6 +11,8 @@ import org.bukkit.inventory.Recipe;
 import org.bukkit.inventory.ShapedRecipe;
 import org.bukkit.inventory.ShapelessRecipe;
 import org.bukkit.inventory.meta.ArmorMeta;
+import org.bukkit.inventory.meta.EnchantmentStorageMeta;
+import org.bukkit.inventory.meta.ItemMeta;
 import org.bukkit.inventory.meta.trim.ArmorTrim;
 import org.bukkit.inventory.meta.trim.TrimMaterial;
 import org.jetbrains.annotations.NotNull;
@@ -44,6 +47,51 @@ public final class SalvageHelper {
         trimMaterialToMaterial.put(TrimMaterial.REDSTONE, Material.REDSTONE);
     }
 
+    /**
+     * Gets salvage for an enchanted book
+     *
+     * @param itemStack <p>The enchanted book(s) to salvage</p>
+     * @return <p>The resulting salvage</p>
+     * @throws RuntimeException <p>If generated enchanted book metadata is null</p>
+     */
+    @Nullable
+    public static List<ItemStack> getEnchantedBookSalvage(@NotNull ItemStack itemStack) {
+        ItemMeta meta = itemStack.getItemMeta();
+        List<ItemStack> output = new ArrayList<>();
+
+        if (!(meta instanceof EnchantmentStorageMeta enchantmentStorageMeta)) {
+            return null;
+        }
+
+        Map<Enchantment, Integer> enchantmentMap = enchantmentStorageMeta.getStoredEnchants();
+        for (Map.Entry<Enchantment, Integer> enchantmentEntry : enchantmentMap.entrySet()) {
+            EnchantmentStorageMeta enchantmentMeta = (EnchantmentStorageMeta) Bukkit.getServer().getItemFactory().getItemMeta(Material.ENCHANTED_BOOK);
+            if (enchantmentMeta == null) {
+                throw new RuntimeException("Unable to create enchanted book metadata.");
+            }
+            enchantmentMeta.addStoredEnchant(enchantmentEntry.getKey(), enchantmentEntry.getValue(), true);
+            ItemStack newBook = new ItemStack(Material.ENCHANTED_BOOK, 1);
+            newBook.setItemMeta(enchantmentMeta);
+            output.add(newBook);
+        }
+
+        return output;
+    }
+
+    /**
+     * Gets the number of enchantments applied to an enchanted book
+     *
+     * @param itemStack <p>The enchanted book to check</p>
+     * @return <p>The number of enchantments, or -1 if not an enchanted book</p>
+     */
+    public static int getEnchantmentCount(@NotNull ItemStack itemStack) {
+        ItemMeta meta = itemStack.getItemMeta();
+        if (!(meta instanceof EnchantmentStorageMeta enchantmentStorageMeta)) {
+            return -1;
+        }
+        return enchantmentStorageMeta.getStoredEnchants().size();
+    }
+
     /**
      * Gets salvage for a given netherite item
      *
@@ -88,6 +136,8 @@ public final class SalvageHelper {
         } else {
             return null;
         }
+        // Note: While depreciated in Spigot, the new method is not available for Paper
+        @SuppressWarnings("deprecation")
         Material patternMaterial = Material.matchMaterial(armorTrim.getPattern().getKey().getKey() +
                 "_ARMOR_TRIM_SMITHING_TEMPLATE");
         if (patternMaterial != null) {

src/main/java/net/knarcraft/blacksmith/util/TabCompleteValuesHelper.java

@@ -38,6 +38,8 @@ public final class TabCompleteValuesHelper {
             case MATERIAL -> getAllReforgeAbleMaterialNames();
             case ENCHANTMENT, ENCHANTMENT_LIST -> getAllEnchantments();
             case STRING_LIST -> List.of("*_SHOVEL,*_PICKAXE,*_AXE,*_HOE,*_SWORD:STICK,SMITHING_TABLE:*_PLANKS");
+            // TODO: Change this to something that makes sense
+            case ADVANCED_COST -> List.of();
         };
     }
 
@@ -77,6 +79,8 @@ public final class TabCompleteValuesHelper {
 
         List<String> enchantments = new ArrayList<>();
         for (Enchantment enchantment : enchantmentRegistry) {
+            // Note: While depreciated in Spigot, the new method is not available for Paper
+            //noinspection deprecation
             enchantments.add(enchantment.getKey().getKey());
         }
         return enchantments;

src/main/java/net/knarcraft/blacksmith/util/TypeValidationHelper.java

@@ -36,7 +36,8 @@ public final class TypeValidationHelper {
                 case STRING -> isNonEmptyString(value, sender);
                 case POSITIVE_INTEGER -> isPositiveInteger(value, sender);
                 case PERCENTAGE -> isPercentage(value, sender);
-                case BOOLEAN -> true;
+                // TODO: Implement proper advanced cost checking
+                case BOOLEAN, ADVANCED_COST -> true;
                 case REFORGE_ABLE_ITEMS, STRING_LIST -> isStringList(value, sender);
                 case MATERIAL -> isMaterial(value, sender);
                 case ENCHANTMENT -> isEnchantment(value, sender);

src/main/resources/config.yml

@@ -141,6 +141,20 @@ scrapper:
     
     # The cost of using the scrapper to remove netherite from an item
     netheriteSalvagePrice: 15
+    
+    # The cost of splitting an enchanted book into several books
+    enchantedBookSalvagePrice: 15
+    
+    # The mathematical formula for salvage cost increase when continually used within the same hour. This is necessary 
+    # for some servers where items can be easily farmed. Set to {cost} to disable behavior.
+    salvageCostIncrease: "{cost}*{timesUsed}"
+    
+    # The mathematical formula for salvage cooldown increase when continually used within the same hour. This is
+    # necessary for some servers where items can be easily farmed. Set to {cooldown} to disable behavior.
+    salvageCooldownIncrease: "{cooldown}*{timesUsed}"
+
+    # Whether to multiply the enchanted book salvage price with the number of enchantments on the book
+    multiplyEnchantedBookSalvageCost: false
   
   # The settings which are set to any new scrapper NPC. To change any of these settings for an existing NPC, you must 
   # change the Citizens NPC file, or use the /scrapper command
@@ -182,6 +196,9 @@ scrapper:
     # Whether to enable salvaging of netherite items
     salvageNetherite: true
     
+    # Whether to enable salvaging an enchanted books with several enchantments into several books with one enchantment
+    splitEnchantedBook: false
+    
     # Default values for messages used by NPCs
     messages:
       # The message to display when another player is using the scrapper
@@ -226,6 +243,9 @@ scrapper:
       # The message to display when explaining the shown item's netherite salvage cost
       costMessageNetherite: "&eIt will cost &a{cost}&e to salvage that &a{item}&e into diamond!"
       
+      # The message to display when explaining the shown enchanted book's salvage cost
+      costMessageEnchantedBook: "&eIt will cost &a{cost}&e to salvage that enchanted book!"
+      
       # The yield message to display if trying to salvage a non-damaged item
       fullSalvageMessage: "&aI should be able to extract all components from that pristine item.&r"
       
@@ -244,5 +264,11 @@ scrapper:
       # The message to display when asked to salvage netherite items, and that option is disabled
       cannotSalvageNetheriteMessage: "&cI'm sorry, but I'm unable to salvage netherite items!"
       
+      # The message displayed when explaining that enchanted book salvage is disabled
+      cannotSalvageEnchantedBookMessage: "&cI'm sorry, but I'm unable to salvage enchanted books!"
+      
+      # The message displayed when a player attempts to  salvage an enchanted book with a single enchantment
+      cannotSplitEnchantedBookFurtherMessage: "&cI'm sorry, but I cannot salvage that enchanted book any further"
+      
       # The message to display when a scrapper is clicked with an empty hand
       noItemMessage: "Please present the item you want to salvage"

src/main/resources/strings.yml

@@ -43,7 +43,7 @@ en:
   # The format used when displaying any duration remaining
   DURATION_FORMAT: "in {time} {unit}"
   # The format used when NPCs talk to players ({npc} = The NPC's name, {message} is the actual message contents)
-  NPC_TALK_FORMAT: "&a[{npc}] -> You:&r {message}"
+  NPC_TALK_FORMAT: "&a[{npc}&r&a] -> You:&r {message}"
   # Translation of the duration of less than a second
   UNIT_NOW: "imminently"
   # Translation of seconds in singular form
@@ -89,4 +89,6 @@ en:
   # The text shown if the player has to wait for more than 5 minutes
   INTERVAL_MORE_THAN_5_MINUTES: "in quite a while"
   # The marker shown when displaying values overridden for the selected NPC (not shown if the NPC inherits the default value)
-  SETTING_OVERRIDDEN_MARKER: " [NPC]"
+  SETTING_OVERRIDDEN_MARKER: " [NPC]"
+  # The translation of the text displayed when a cost is expected, but a non-number is provided
+  DOUBLE_COST_REQUIRED: "You must supply a numeric (double) cost"