Legal Question in Consumer Law in New Jersey

Re: credit card purchases

There is no law against doing that, but the practice probably violates the dealer's agreement with the credit card company. Most credit card agreements require that the merchant offer their products at the same price regardless of whether the buyer pays with cash or credit. Some agreements preclude any distinction between cash and credit customers. If you have been asked to pay more in order to use a credit card, report the practice to the credit card company.

See also: http://info.corbettlaw.net/lawguru.htm