Make or Buy Terry Inc. manufactures machine parts for aircraft engines. CEO Bucky Walters is considering an offer from a subcontractor to provide 2,100 units of product OP89 for $94,500. If Terry does not purchase these parts from the subcontractor, it must continue to produce them in-house with these costs: Calculate the relevant cost per unit for producing the product. Calculate the additional total (not per unit) cost or savings of producing the product internally versus purchasing the product externally, from a supplier. Additional cost of producing internally