Just thought up an idea, I don't know if anyone has thought of this before.
Basing on how many times you have gotten. "All thine hard work" The upkeep goes down by maybe.... 100? or 50? on that certain item. But it would only maybe scale up to 200.
I dont know. Theres alot of room for change in this so post your idea if you want.
Or maybe it could be based on a percent of the price of the item?
You decide.