Answer: $12
Step-by-step explanation:
In selling the obsolete goods, the company will incur Variable Marketing costs and the alternative will be to throw the goods away.
The relevant costs they will incur are therefore the Variable Marketing costs alone.
The lowest amount that a company should accept for a good is the price that equals it's cost so that they may at least Break-Even.
Seeing as the Variable Marketing Costs are the only relevant cost then the lowest they should accept is the Variable Marketing Costs of $12.