GMod In-Game Credit Store System

Hello, I am wondering if there is any type of credit based donation system out there? It is for my server, I have been trying to find one but it is not working out for me. Certain servers have it like Divinity Roleplay. If you guys have any idea of a place that has an in-game system like this, please tell me. Here is a couple examples:

Token Store:


There’s some ones on ScriptFodder that I bet with some modifying you can get to your liking.