sflagel must be an astroturfer. Seriously.
In my country retailers are able to add the credit card fee to a transaction, and for those that do, it is usually 1.5-2%.
iIf amex is 7% then that would explain why it is close to invisible in this country compared with visa and mastercard.
Anyway, in the case of CurrentC vendors, the retail price of the product will be the same, there may or may not be discounts at the cashier, but COUPONS!!+!.
Coupons you would probably...