Valley Trout Farms ordered fish food from Rangen. Both parties were merchants. The invoice that was sent with the order stated that a specified charge—a percentage common in the industry—would be added to any unpaid bills. Valley Trout Farms did not pay for the food and did not make any objection to the late charge stated in the invoice. When sued by Rangen, Valley Trout Farms claimed that it had never agreed to the late charge and therefore was not required to pay it. Is Valley Trout Farms correct? [Rangen, Inc. v Valley Trout Farms, Inc., 658 P2d 955 (Idaho)]