These guys mandate a $10 minimum for credit card purchases. Although their contract with the credit card companies specifically says this is against their rules.
The owner was rude when I tried to make a purchase with a credit card and would not budge on the $10 minimum. he wanted me to buy more stuff instead.
It seems to me that they want to be able to accept credit cards, but they don't want to have to pay for this benefit... it is the cost of doing business.