A company purchased 100 units for $20 each on January 31. It purchased 100 units for $30 on February 28. It sold 150 units for $45 each from March 1 through December 31. If the company uses the Last-In, First-Out inventory costing method, what is the amount of ending inventory on December 31?
$1,500
$1,250
$1,000
$2,250