Lee Corporation manufactures and sells party items. The following representative direct labor hours and production costs are provided for a four-month period: Month Direct Labor Hours Production Costs January 3,500 $15,000 February 4,800 $17,500 March 6,000 $20,000 April 4,800 $17,500 What is the best estimate of production costs using the high-low method if the expected direct labor is 5,000 labor hours?