An office building is currently for sale, and you are thinking of purchasing it. From your extensive market research and knowledge, you know the net operating income for this year is $250,000. You expect the net operating income will grow by 5% in the first five years, 3% in the subsequent five years, and 1.5% for every year after. If you are considering a 15- year investment window and desire a 20% rate of return, how much should you pay for the building?