You paid your rent with coins, but then the owner just went and returned them to the bank. Same end result as if you would have just added the to the bank yourself. Only difference being that someone else deposited them instead of you. You weren't "circulating" them.


Costco sometimes does give cash back instead of a credit. But it'll get flagged quick and you'll lose your Costco membership.

But to do that is more wrong than buying coins from the mint IMO.