story
All fees are a way of raising a price.
There is supposed to be a difference between markup and a fee. We don't have to hash out what exactly the difference is, just observe that there is a difference.
It's a common grift to hide part of the price in unadvertised "fees" so that consumers will have a harder time comparing options but it is just that, a grift. It's deception.
A per-transaction credit card fee doesn't raise the unit price. Getting hung up on the evolving details of gas stations and credit card processing isn't the point.