Ok...... so........................
First off, you'll have to be talking to a "specialty" kind of a shop for them to even want to do it. Collision type shops do great work, but they are an assembly line business: Their bread and butter is get the new Civic or Suburban in that's been crunched, order the readily available crash parts that will there the next day, fix the damage, swap the parts, spray it and get it out of there. That's how they make money and they can't make money on stuff like your CUCV because it's outside of their comfort zone/wheelhouse/etc. So it's possible the price you were quoted was the "we don't want to do this job, so we're gonna' price it high" price.
However, that being said.....................
My Father has a '68 Chevelle and it's really nice. Gorgeous body with very minimal issues. Corrosion above the wheel lips on the quarters, bottom of the fenders need patches. That's about it. We have a friend who does really high end metalwork on antiques-stuff like Mercedes Gullwings, Porsche 356s, Plymouth Superbirds, etc. He is going to blast the car and put quarters on it and have it 100% ready for the paint shop.
I went around to all the people I know in the antique car industry and got referrals for about half a dozen shops and I went and visited them. I explained that I was in the industry and that when I say the body they're going to get it going to be perfect and ready for block sanding, I meant it. There are a lot of home hobbyists who think their vehicle is a lot better than it really is.
Out of the 6 shops I visited, I found 3 willing to do it and of those 3, 2 I felt comfortable with.
The car will be in primer, with the body completely disassembled, on a rotisserie. So the painters can immediately work on it. No disassembly or metalwork required. It is a very simple car: It is not a SS, so it doesn't have black rear filler panel or lower body paint. It doesn't have any striped or a vinyl top. Since it's a GM car, it's a simple semi gloss black on the bottom of the car, the firewall, etc. The trunk is splatter paint. They'll be painting the fenders, hood, inner fenders, radiator core support and wheels separate from the car. I asked that the paint shop sand and buff the paint. The doors will already be hung and adjusted (metal shop is rebuilding hinges and hanging doors).
Every quote I got was $8-10K. That is for high end paint and primer, PPG. The color isn't anything special (meaning it's not expensive).
Keep in mind this is for a vehicle that's coming to them already stripped to the bare body, already media blasted, all the metalwork done and in the primer of their choosing. They can receive the car and begin block sanding it that day. And everyone I've spoken with said that price is what could be expected.
I do some paint work and if I had to prep it, I would not touch a CUCV for less than $7500-10K. And I'll tell you why.
The only way I'd do it would be to have the whole truck media blasted, which means a lot of disassembly and prep work for the blasting and a lot of cleanup afterwards. Like everyone said, CARC is hard to strip. Once it was stripped and cleaned, then do any necessary metalwork. Then prime it, then depending how smooth you want it, block it, then the color (and all the tape work for the 2 colors), then the clear, then sanding and buffing it. Then reassembly. I'll bet my cost on the stripping alone would be $2500.
That is an astonishing amount of work. Think about all the tape work for the engine compartment-you have to shoot the inside of the front fenders. They're body color to where they meet the inner fenders. With all the work on the front end, you'd probably be better off just pulling the front clip off and panel painting it. That will also give the chance to detail the frame, wheelhouses, etc.
I can paint a full size vehicle in a day, a weekend if it has a clear coat. But the work that goes in before and after? Months.
Chevelle: