Kando Company currently pays $$13$ per unit to buy a part for a product it manufactures. Instead, Kando could make the part for per unit costs of $$6$ for direct materials, $$4$ for direct labor, and $$2$ for incremental overhead. Kando normally applies overhead costs using a predetermined rate of $200\%$ of direct labor cost.

$($a$)$ Prepare a make or buy analysis of costs for this part.

$($b$)$ Should Kando make or buy the part?