$20.$Welt entered into a contract with Carbonara for the purchase of two dozen ultralight bike frames that he planned to resell from his retail bike shop. The price was $$600$ each. The parties wrote out all the terms os their contract and each signed. Later welt learned that he could acquire similar frames for $$525$ each. Welt told Carbonaro that if it wanted to maintain Welts goodwill it would reduce the price to $$525.$ Carbonaro agreed. What is the consideration in the original contract? Is maintaining goodwill something which has legal value? Is the price of $$525$ enforceable? Why or why not?