Spahr Company produces a part that is used in the manufacture of one of its products. The unit manufacturing costs of this part, assuming a production level of 5,000 units, are as follows: Erickson Company has offered to sell 5,000 units of the same part to Spahr Company for $11 per unit. Assuming the company has no other use for its facilities, what should Spahr Company do? Buy from Erickson and save $1 per unit. Make the part and save $5 per unit. Make the part and save $2 per unit. Make the part and save $1 per unit