Xenforo RPG Shop

I would like a xenforo addon that is essentially a shop where I can create a number of unique Skills and Items, each with a rank (1, 2, 3, 4, 5). Users can buy these items with points_mp or points_gp or a mix of both (these are generated from a point addon already integrated on the forum and appear in the database, so you can just use them). The purchased item would then appear in their inventory and in the postbit. If they ‘upgrade’ an item to the next rank, then the addon would delete the previous rank so they would only have the highest ranked item in that category. I also need a resell function for the item. I would also like to set a cap of how many item users can have each category. Let me walk you through how it is used. - New account - Goes to the shop and choose 3 starter Skills - User chooses Skills: Slash 1, Wind Magic 1, Shield 1 - Posts, earns points_mp and points_gp - With enough points_mp, the user goes back to the shop to upgrade Slash 1 to Slash 2 - User buys Armor 1 with points_gp Please do not hesitate to reach out to me for more info. PS. The logic of this addon is heavily inspired by another established mod, which I can show you, it simply doesn't do what I want.