At lot of gas stations in my area offer gas cheaper if you pay cash. Usually it's around a 10 cent difference in price. Is this something that shouldn't be happening?
Yes, these things are mathematically equivalent. And yet, that's what the law said.
My wife is a government lawyer, and I sometimes reflect that our jobs both ultimately involve writing words that do stuff.
It wasn't the law[1] but rather a contractual restriction on surchages. This settlement with VISA and MasterCard removes that restriction. It doesn't apply to other companies like American Express.
[1] Some states did and still do prohibit credit card surchages.
There's a grocery discount chain by me (Woodmans) that simply doesn't take credit cards because of the fees. If you want to pay by plastic you will pay by Debit Card with PIN. Walmart's discount chain (Sam's Club) has the same policy except for MasterCard.