relevant costing

A company purchased a machine several years ago for £79,000. Its written down value is now £37,000. The
machine is no longer used on normal production work and it could be sold now for £8,000.
A one-off contract is being considered which would make use of this machine for six months. After this time the
machine would be sold for £6,000.

What is the relevant cost of the machine to the contract?

For my calculation will be the following:
Sold now $8,000
Cost of disposing $6,000

relevant cost will be nil, is because relevant costing is excluding the loss of disposal. But it seems like the answer is wrong.