Delta Diamonds uses a periodic inventory sistem. The company had five one- carat diamonds available for sale this year: one was purchased on June 1 for $500, two were purchased on July 9 for $550, and two were purchased on September 23 for $600 each. On December 24, it sold one of the diamonds that was purchased on July 9. Using the fifo method, its ending inventory ( after the December 24 sale) equals