Crane (P) submitted a proposal to build a deaerator for $5,238.00. A price of $5,217 was agreed to, however, Progressive (D) was later informed that because of escalating material costs the price had to be raised to $7350.00. D agreed to the higher price and submitted a second purchase order for the greater amount. The machine was delivered and then asserted that only the original price amount was due and not the increased amount. P sued.