Mary Williamson, an engineer is allowing for the purchase of a copy machine for her consulting office. The copy machine will cost $2,000 and have a resale value of $400 at the end of its 5-year-life. Having the machine in the office will decrease copy costs by $1,000 a year. Copy machine maintenance may be $500 for the first year and will increase by $100 each year. Evaluate if it is worth buying at an interest rate of 6%?