A company purchased 200 units for $40 each on January 31 . It purchased 200 units for $30 each on February 28 . It sold a total of 250 units for \$100 each from March 1 through December 31 . If the company uses the last-in, first-out (LIFO) inventory costing method, calculate the cost of ending inventory on December 31. (Assume that the company uses a perpetual inventory system.) $6000 $4500 $150 $9000