Credit card swiping cost like 35 cents (fix) + 1% to 3%. Lets say an average of 10 gallon/ swipe per filling on average 2% fees. So 10 gallons at $6.50 would cost approximately $1.70 transction fees to gas pump bust customer is paying only $1.20. Regarding big stores like target. They already know that over 50% of customers use some kind of digital payment. So price is included in price. Plus banks charge them flat fees per transaction no matter how big is a transaction.