Really all down to the prep work. My race car shell only cost me the paint, the labour was already included in the price so it was basically less the £200, I believe the labour involved would have been no more then a few hours. Having said that the car will still need a blow over and final prep when we complete the build which ISTR will cost me about £600. The majority of that £5000 cost will be in the work required to strip and prepare the car. Personally having done this to build a race car, if I was doing a road car I would do the same and strip the car back to a bare shell, acid dip and rebuild over perhaps a winter. The cost would be horrific if paying someone else to do all that prep work though, ISTR my brother said of the couple of reshells he did before my race car it was circa 200 hours work. Even if one got a big job discount of say £25 ph that is still a lot of money.
I don't think its worthwhile respraying any of our cars unless one is 100% about the underlying bodywork, as Mark says it can become a horror movie. Both of the wings from my S2 for example scrapped, and I hoped to sell them, they looked OK on the car.