A company sells motherboards for personal computers. For quantities up through 25, the firm charges $350 per board; for quantities between 26 and 50, it charges $315 for each board purchased beyond 25; and it charges $285 each for the additional quantities over 50. A large communications firm expects to require these motherboards for the next 10 years at a rate of at least 250 per year. Order setup costs are $25 and holding costs are based on a 20 percent annual interest rate. What should be the size of the order?