I assume the valspar mentioned earlier is a proper automotive finish (multi-stage with clear coat, 2 part with hardener), not typical to what most folks are painting military vehicles with. I've only done the spray cans from rapco, but assume their bulk paint is just basic one part enamel. Nothing wrong with that for what most folks are after, but it's not an automotive paint system like you see with passenger vehicles. It's really like comparing apples to organges, totally different products.
It's probably been 15-20 years since I have priced automotive paint and the products have changed, but materials to do a car with something like sikkens would be over $500 back then. It wouldn't surprise me if materials are over $1000 these days. $2000 sounds crazy, but maybe. Regardless, I'd never use that kind of paint system on a hmmwv, but I'm sure some people do. All the rivets and bolts on the body pretty much guarantee that you'd never have a durable high end paint job. For what it's worth, I have no plans to paint my truck. For me, the original carc w/ dings and scratches add character and I don't need to worry about someone adding more scratches.