Relevant costs in a make$-$vs$.-$buy decision of a part include:

Multiple Choice

Corporate $($i$.$e$.,$ headquarter$)$ salaries.

The cost of currently used manufacturing capacity that has alternative uses if the part is outsourced.

Corporate headquarter costs that will be allocated differently depending on the decision option chosen.

Factory$-$related insurance cost.

Setup overhead costs for the manufacture of the product using the outsourced part.