32 Amco Convenience Store purchases 500 hammers a year for its inventory from its supplier, who offers pricing at quantity discounts. The quantities and pricing from this supplier are shown in the following table:

ORDER QUANTITY UNIT PRICE 0–149 $12.00 150–349 $11.50 350–599 $10.50 600 or more $ 9.80 The cost for Amco to place an order is $60, and the cost to store a hammer in inventory for a year is $2.

What quantity should Amco order?