Koolau
Give me a museum and I'll fill it. (Picasso) Give me a forum ...
Yes, and that would be legal. Going the other direction (a surcharge for using a card) would not.
According to Visa:
Your gummint looking out for you.
"I'm from the gummint. I'm here to help."
Mentioned before that businesses can negotiate (especially using their trade associations) much lower costs for their use of credit cards. Those that won't "play" can be dropped. Any bidness paying 3.5% for credit cards is over paying IMHO.