A particular raw material is available at the following prices: 1) $3.10 for orders of less than 1000 2) $3.08 for orders between 1000 and 1999 3) $3.07 for orders 2000 and larger Annual demand is 12000 items, order cost is $25, and holding cost is 20% of the item's cost per year. What is the economic order quantity?