Alpha has 300 units of an obsolete part with a regular selling price of 20. The UVC to produce them was 5. The company has several options.

One option is that a company has offered to buy the part at 4 each.

A second option is that Alpha could do additional work on the part for 8 per unit and then sell them for 11 per unit.

A third option is to write the part off taking the loss.

What is the differential profit per unit for the best solution for Alpha?