Conn. Gen. Stat. §42-133ff
(c) Nothing in this section shall prohibit any seller from offering a discount to a buyer to induce such buyer to pay by cash, debit card, check or similar means rather than by credit card. In furtherance of the legislative findings contained in §42-133j, no existing or future contract or agreement shall prohibit a gasoline retailer or distributor from offering a discount to a buyer based upon the method of payment by such buyer for such gasoline. Any provision in such contract or agreement prohibiting such retailer or distributor from offering such discount is void and without effect as contrary to public policy.