(27) Lisa was a sales agent for DRG. By contract, DRG agreed to pay Lisa a $1,500 monthly salary plus a commission of 10 percent of the price of goods sold by her. Prior to her discharge (1) Lisa was owed one month's salary; (2) Lisa sold goods for $10,000; and (3) Lisa incurred $50 phone charges in making sales. Prior to her discharge, Lisa had also been negotiating a $20,000 sale of goods, but the sale was never completed. How much does DRG owe Lisa?