We are evaluating a project that costs $732,000, has a six-year life, and has no salvage value. Assume that depreciation is straight-line to zero over the life of the project. Sales are projected at 55,000 units per year. Price per unit is $60, variable cost per unit is $30, and fixed costs are $640,000 per year. The tax rate is 35 percent, and we require a return of 12 percent on this project.

Calculate the change in NPV if sales were to drop by 500 units.