diff --git a/mod_examples/README.md b/mod_examples/README.md
index 25b1d75e..e38d5834 100644
--- a/mod_examples/README.md
+++ b/mod_examples/README.md
@@ -41,6 +41,7 @@ To get into shapez.io modding, I highly recommend checking out all of the exampl
 | [modify_existing_building.js](modify_existing_building.js) | Makes the rotator building always unlocked and adds a new statistic to the building panel         | Modifying a builtin building, replacing builtin methods                                         |
 | [modify_ui.js](modify_ui.js)                               | Shows how to add custom IU elements to builtin game states (the Main Menu in this case)           | Extending builtin UI states, Adding CSS                                                         |
 | [pasting.js](pasting.js)                                   | Shows a dialog when pasting text in the game                                                      | Listening to paste events                                                                       |
+| [sandbox.js](sandbox.js)                                   | Makes blueprints free and always unlocked                                                         | Overriding builtin methods                                                                      |
 
 ### Advanced Examples
 
diff --git a/mod_examples/sandbox.js b/mod_examples/sandbox.js
new file mode 100644
index 00000000..d57e1e0e
--- /dev/null
+++ b/mod_examples/sandbox.js
@@ -0,0 +1,21 @@
+// @ts-nocheck
+const METADATA = {
+    website: "https://tobspr.io",
+    author: "tobspr",
+    name: "Sandbox",
+    version: "1",
+    id: "sandbox",
+    description: "Blueprints are always unlocked and cost no money, also all buildings are unlocked",
+    minimumGameVersion: "^1.5.0",
+};
+
+class Mod extends shapez.Mod {
+    init() {
+        this.modInterface.replaceMethod(shapez.Blueprint, "getCost", function () {
+            return 0;
+        });
+        this.modInterface.replaceMethod(shapez.HubGoals, "isRewardUnlocked", function () {
+            return true;
+        });
+    }
+}