Sam Seller and Ben Buyer enter into a K for the purchase and sale of 100 widgets for $500. Upon receipt of the widgets, Ben promptly discovers that they are not as promised. In fact, due to the nonconformity the widgets as delivered are worth no more than $450. With that knowledge, he nevertheless accepts the widgets. He refuses, however, to pay for them. Sam contends that since Ben accepted the widgets Ben is bound to pay the K price of $500. Ben contends that since the widgets were nonconforming Ben's duty to pay was never triggered and he owes nothing. Who is right