In summary

You value the work he's completed (plus materials) - say ?500
That leaves say ?500 of work remaining (nice round ?1,000)
To get in somebody else to carry out the ?500 of work remaining will cost you ?800, he therefore owes you nett ?300
If you haven't paid him any of the ?500, you'll owe him ?200 (you don't pay more than the ?1,000 originally contracted for)
If you've paid him the ?500, that's an issue for you and getting something back from him may be problematic
Go straight to small claims court for any outstanding debt, plus costs plus interest

Posted By: Mr Crowley, Oct 3, 20:21:32