When I worked at high end shop (literally next to chip foose, who referred us business) we were 10 grand to get in the door. Usually went up when the car got naked. It was show car quality, in so cal car went to pebble beach won best of paint.... yada yada yada..... We used high quality materials and on average we had over 3000 in just materials at our cost.

Most show cars received over 200 hours of documented labor- and yes a show cars usually went over 20,000$ The most expensive car was a 31 ford coupe-
We did most of the cars on that page.

http://www.wheelersspeedshop.com/projects.html

IIRC 27,000$, I personally did ALOT of the body work, and color sanded it and polished it and assembled it. It was through wheelers speed shop who was 1/2 block away from us. Great guys there!

We refused to do the white flames on it, so we painted it, it left came back with those things on it came back and we finished it.

The base coat on that car was 700$ a gallon. 3 gallons. just BASE!!!!

If we didn't strip a car (very rare) we could get it done for under 10k. also all cars were in and out of our shop within 3 months.
I left the shop as we got in a 1970 cuda convertible 440 car.... I wanted to stay just a bit longer, but couldn't