Suppose an investor is interested in purchasing the following income-producing property at a current market price of $450,000. The prospective buyer has estimated the expected cash flows over the next four years to be as follows: year 1 = $40,000; year 2 = $45,000; year 3 = $50,000; year 4 = $55,000. If the estimated proceeds from selling the property at the end of year 4 is $500,000, what is the NPV of the project?