A $25,000 machine that has been used for one year has a salvage value of $16,000 now, which will drop by $4,000 per year. The maintenance costs for the next 4 years are $1,250, $1,450, $1,750 and $2,250. When the machine is sold, it will cost $2,000 to remove and sell. When machine was purchased, the estimated salvage in 5 years was $3,500. What is the marginal cost for each year