Harbortown Marine Products $($HMP$)$ manufactures and sells various fixtures for boat cabins. One fixture uses a specialized fitting that is not used in any other HMP product. The management of HMP has considered outsourcing the fitting for several years but has never identified a suitable supplier. HMP has collected the following data on the cost of the fitting:

Materials $ $6\mathrm{.}55$

Labor $4\mathrm{.}95$

Manufacturing overhead $14\mathrm{.}55$

Total $ $26\mathrm{.}05$

Rivard Fittings, a local auto supplier, contacts HMP and tells them that because of the loss of one of Rivard's customers, there is enough capacity to produce up to $5,000$ units of the fitting monthly. Rivard has offered to sell HMP any quantity $($up to $5,000$ units monthly$)$ at a price of $$20\mathrm{.}45$ per fitting.

If Rivard supplies all of the $3,060$ fittings currently produced by HMP$,$ HMP will avoid all of the variable overhead associated with the fitting and one$-$third of the fixed overhead. Management estimates that variable overhead for the fitting is $$4\mathrm{.}95$ per unit.

Required:

Prepare a schedule that shows the differential costs.

Should HMP continue to make the fittings or buy them from Rivard Fittings?