Stephans Corporation currently manufactures a subassembly for its main product. The costs per unit are as follows: Bill Company has contacted Stephans with an offer to sell them 5,000 of the subassemblies for $22.00 each. Stephans will eliminate $25,000 of fixed overhead if it accepts the proposal. Should Stephans make or buy the subassemblies? What is the difference between the two alternatives