I think they quoted wheels at about £40 each, but don't forget that you need to remove the bearings from them before getting them done, so factor in the cost of a new set of bearings (and fitting) to the overall cost.
I'm tempted to have my wheels painted black (as I can probably get them done free) rather than powder coated. You don't need to remove the bearings as they mask them off, so might be a cheaper / easier solution?
I'd rather die peacefully in my sleep like my Grandfather, than screaming in terror like his passengers.- Jim Harkins