Market Press User Account Balance

I need some help in figuring out a solution.

I have installed MarketPress and was hoping it had a user interface so they could see their purchases and mainly, have an account balance. I want to find a plugin that keeps track of balances and spending. If I add an item, and they have money in their account, they can purchase that item. I would also like to add money to their accounts from time to time. I have played with cube points but need something more robust. Is there anything that can be added to marketpress to make this work?