A mechanical engineer must recommend a new heating system to a commercial building owner. The owner intends to sell the building in 15 years. A gas fired furnace option has a design life of 5 years, an initial cost of $10,000, a replacement cost of $5,000 and annual operating costs of $3,500, but adds no value to the building when sold. A geothermal heat pump system has a design life of 10 years, an initial cost of $17,000, a replacement cost of $9,000, annual operating costs of $2,500, and increases the value of the building by $6,000, when it is sold at the end of year 15. 

Determine the PV of costs for the option the engineer should recommend at an interest rate of 7.9%. 

Express your answer in $ to the nearest $100.