we had to have our vauxhall zafiras resprayed all along one side just recently.we used the garage were we bought it from to do the job and they charged us 750 pounds just for that .you are probably looking at 2000 pounds probably for a respray if you use a garage to do it.if you use an in-dependant car paint sprayer ,then you are looking at 1000 pounds at least,i would get out the yellow pages and look under in dependant paint sprayers for cars and get a few quotes.garages charge the earth as they have a lot of over heads
an independent person does not have so many over heads and can afford to undercut the garages good luck