Right, the exploit I was thinking of could be solved pretty easily. The exploit that most have thought about is someone buys a load of cent, spins it all, sells the stuff they dont want, rinse and repeat. What if when an item was sold it gave a different kind of cent, like gold cent is the main one and silver cent is the sold items one, and that ammy can only be bought with gold cent, not silver, that would cut out that exploit.