Nguyen Construction purchased a poured concrete form from Guzman Concrete Forms, Inc. Nguyen purchased the concrete form by placing a phone call to Guzman in Madison, Wisconsin. Guzman delivered the concrete form with an invoice stating the terms of the sale required payment within 30 days and a 1 1/2 % interest per month finance charge would be charged on accounts over 30 days. When Nguyen failed to pay the invoice on time, interest was charged according to this rate. Later, Nguyen refused to pay the accumulated interest charge claiming there was not a "meeting of the minds" regarding the finance charge in any conversation prior to the sale. The trial court concluded that the finance charge was in fact an "additional term" added by Guzman when it accepted Nguyen's purchase order. Is there a valid contract? What are the legal implications of this "additional term"? Does Nguyen owe the interest accrued? Be sure to discuss Uniform Commercial Code Section 2-207 in general and with regard to this situation.)