A machine was purchased five years ago at a cost of $60,000. It currently has a market value of $10,000. The current book value is $15,000. It can function for another 2 years and will have an annual operating expense of $10,000 next year and $12,000 the following year. The market value one year from now is estimated to be $5,000 and it would be $2000 two years from now. The old machine can be replaced with an improved version that will cost $80,000 and will have annual operating expenses of $6,000. This new machine is expected to have a market value of $5,000 at the end of a 8-year economic life. It is thought that this type of machine would be needed indefinitely. Should the old machine be replaced now, a year from now, or two years from now? (Before-tax MARR is 12% per year compounded yearly)