Sheridan Company purchases sails and produces sailboats. It currently produces $1,270$ sailboats per year, operating at normal capacity, which is about $80\%$ of full capacity. Sheridan purchases sails at $$268$ each, but the company is considering using the excess capacity to manufacture the sails instead. The manufacturing cost per sail would be $$98$ for direct materials, $$86$ for direct labor, and $$90$ for total manufacturing overhead. The $$90$ total manufacturing overhead includes $$78,740$ of annual fixed overhead that is allocated using normal capacity.

The president of Sheridan has come to you for advice. $"$It would cost me $$274$ to make the sails," she says, "but only $$268$ to buy them. Should I continue buying them, or have I missed something?"

$($a$)$

Prepare a per unit analysis of the differential costs. $($Enter negative amounts using either a negative sign preceding the number eg$.-45$ or parentheses e$.$g$.(45).)$

Should Sheridan make or buy the sails?