So the other day I stopped at a BP gas station in Overland Park Kansas to buy some gas. I observed something that somehow I don't think is legal. They were selling premium grade gasoline at $2.80 per gallon if you paid with cash, and $2.83 per gallon if you paid with a credit card. I've never seen anything like this before where gas is one price if you use cash to pay for it, and the same gas is more expensive if you use a credit card to pay for it. I'm not a lawyer, but somehow that just doesn't seem right. Anyone care to enlighten me?