If I wanted some cosmetic work on my car - alloys tidying up, few scratches sorting, T cutting etc I’d probably do a bit of internet searching which would give figures, say £100-200. If I went to my normal dealer (called, eg Martials of Oxford) and they quoted £900 I might think of going elsewhere or saying ‘don’t be ridiculous, you’re having a laugh’.
Paint the thing by all means, make it look good, but pay a reasonable price.