What about a cash discount?

Small-Business Owners Lobby to Cut Credit Card Fees

Excerpt:

A typical merchant card payment has two parts: an “interchange fee,” which includes an average 1.7 percent of the sale price and a flat per-transaction fee, and a separate fee that goes to the merchant’s bank. Take, for example, a driver who pays for a $1,000 car repair with a credit card. The bank that issued the consumer’s card receives an interchange fee of $17.10 (including a 10-cent flat fee), while the repair shop’s bank gets $4, or four-tenths of 1 percent of the total sale. The repair shop pockets $978.90.

Comment: I would like to see retailers offer a discount for cash.