An economy produces computer chips and fish. In 2014, one pound of fish costs $10, a computer chip costs $10, and the economy produces 10 pounds of fish and 10 computer chips. In 2015, when the economy produces 5 pounds of fish and 20 computer chips, one pound of fish costs $20 and a computer chip costs $5. Real GDP in 2015 (at 2014 prices) was _____ dollars.