[Kia]

1. Make a simple Point System which saves points in a SQL Database. Can be done by reading some tutorials.
2. Create a shop using this points containing the Items you want, save their state also in SQL.

This is similar to my Bunnyhop Challenge Mod, where you can finish Bunnyhop Maps using diffrent Airaccelerates ( so different Difficulties ) and gain points to spend on Trails, Hats and Models.
If you have other payment options than PayPal please contact me.