Pharoah Street Inc. makes unfinished bookcases that it sells for $59. Production costs are $38 variable and $10 fixed. Because it has unused capacity, Pharoah Street is considering finishing the bookcases and selling them for $71. Variable finishing costs are expected to be $7 per unit with no increase in fixed costs. Prepare an analysis on a per unit basis showing whether Pharoah Street should sell unfinished or finished bookcases.