modify it for special use by your firm . The chromatography , which falls into the MACRS 3 - year class , would be sold after 3 years for $ 56 , 000 . The MACRS rates for the first 3 years are 0. 3.3.33 , 0. 4445 and 0. 1481 . Use of the equipment would require an increase in net working capital ( spare parts inventory ) of $9 , 600 . The machine would have no effect on revenues , but it is expected to save the firm $64 , 000 per year in before-tax operating costs , mainly labor . The firm's marginal federal - plus-state tax rate is 40%/0