Troy Engines, Ltd., manufactures a variety of engines for use in heavy equipment. The company has always produced all of the necessary parts for its engines, including all of the carburetors. An outside supplier has offered to sell one type of carburetor to Troy Engines, Ltd., for a cost of $35 per unit. To evaluate this offer, Troy Engines, Ltd., has gathered the following information relating to its own cost of producing the carburetor internally: 15,000 units per Per unit year 14 210,000 10 150,000 45,000 90,000 Direct Materials Direct Labor Variable manufacturing overhead Fixed manufacturing overhead, traceable Fixed manufacturing overhead. allocated total cost 3 6 9 135,000 630,000 42 one-third supervisory salaries; two-thirds depreciation of special equipment (no resale value) What are the RELEVANT costs to BUY the carburetors (on a per unit basis)