**** $5000-$10,000 around here depending upon how much body work needs to be done, and how you bring it to them. Since most places charge by the hour, anything you can do to make their lives easier in terms of removing trim, badges, etc.. will make it cheaper.
Black is the hardest color to do a great job with as it shows every little ripple, etc.. due to poor body work. The biggest factor in cost is prep, the paint itself is relatively cheap. If you have lacquer check on your hood or trunklid as many GN's do, it has to be sanded down to bare metal otherwise the cracking will return. It just adds to the cost.. Wet sanding repeatedly, etc.. just takes time. It's a crazy amount of work.
I laughed when a friend of mine took his moms Cutlass Supreme years ago to Earl Shives to get painted for $129, after he got quoted $2000 from a better place (this was back in the 80's..).. It was like an assembly line, with a bunch of guys just masking the car off with newspaper out in the open, quickie sanding, etc... It looked ok from about 150 feet away after it was done, until you saw that they had painted the badges, the trim, the window mouldings, and there was overspray inside the windows... It almost looked like they had run the car through a car wash that used paint instead of water to clean it..
Billy
Montgomery Village, MD