Problem $21\mathrm{.}2$A $($Static$)$ Make or Buy Decision $($LO$21-1,$ LO$21-2,$ LO$21-3,$ LO$21-4)$

Guthrie Generators manufactures a solenoid that it uses in several of its products. Management is considering whether to continue manufacturing the solenoids or to buy them from an outside source. The following information is available:

The company needs $20,000$ solenoids per year. The solenoids can be purchased from an outside supplier at a cost of $$15$ per unit.

The unit cost of manufacturing the solenoids is $$20,$ computed as follows:

$\backslash$table$[[$Direct materials,$$180,000$