Added Price#withMultiplier

eco-api/src/main/java/com/willfp/eco/core/price/ConfiguredPrice.java

@@ -82,6 +82,14 @@ public final class ConfiguredPrice implements Price {
         this.price.setMultiplier(player, multiplier);
     }
 
+    @Override
+    public @NotNull ConfiguredPrice withMultiplier(final double multiplier) {
+        return new ConfiguredPrice(
+                this.price.withMultiplier(multiplier),
+                formatString
+        );
+    }
+
     /**
      * Get the price that this delegates to.
      *

eco-api/src/main/java/com/willfp/eco/core/price/Price.java

@@ -88,4 +88,14 @@ public interface Price {
                                final double multiplier) {
         // Override when needed.
     }
+
+    /**
+     * Copy this price with a given base multiplier.
+     *
+     * @param multiplier The multiplier.
+     */
+    @NotNull
+    default Price withMultiplier(final double multiplier) {
+        return this;
+    }
 }

eco-api/src/main/java/com/willfp/eco/core/price/impl/PriceEconomy.java

@@ -81,4 +81,12 @@ public final class PriceEconomy implements Price {
                               final double multiplier) {
         this.multipliers.put(player.getUniqueId(), multiplier);
     }
+
+    @Override
+    public @NotNull PriceEconomy withMultiplier(double multiplier) {
+        return new PriceEconomy(
+                baseContext,
+                ctx -> function.apply(ctx) * multiplier
+        );
+    }
 }

eco-api/src/main/java/com/willfp/eco/core/price/impl/PriceItem.java

@@ -146,4 +146,13 @@ public final class PriceItem implements Price {
                               final double multiplier) {
         this.multipliers.put(player.getUniqueId(), multiplier);
     }
+
+    @Override
+    public @NotNull PriceItem withMultiplier(double multiplier) {
+        return new PriceItem(
+                baseContext,
+                ctx -> function.apply(ctx) * multiplier,
+                item
+        );
+    }
 }