Might be big for bigger vendors too. I know Oracle extorts at least some merchants at least a few hundred dollars per year per credit card terminal for the privilege (“interface license fee” or some BS) of being able to use it. The more some of these legacy middlemen get taken out of the picture, the better.
The POS terminals for BlueMercury (a national cosmetics chain) are iPad Airs with a tap-to-pay reader bolted on them. This would remove that bulk, expense, and potential point of failure.