A farmer bought a new harvester for $120,000. The harvester's operating expenses averaged $10,000 per year but the harvester saved $40,000 per year in labor costs. It was depreciated over a life of 5 years using the SOYD method, assuming a salvage value of $30,000. The farmer sold the harvester for only $10,000 at the end of the fifth year. Given an income tax rate of 30% and a MARR rate of 5% per year, determine the after-tax net present worth of this investment.