Your firm needs a machine which costs $180,000, and requires $33,000 in maintenance for each year of its 7 year life. After 3 years, this machine will be replaced. The machine falls into the MACRS 7-year class life category. Assume a tax rate of 40% and a discount rate of 13%. If this machine can be sold for $18,000 at the end of year 7, what is the after tax salvage value?