If you did all the prep and I had to shoot the primer and bc/cc on the engine compartment and you supply the materials needed I would charge you $500.

Also why on earth would anyone want to shoot their compartment with single stage. With the far better results of bc/cc and the quality of todays paints I never shoot single stage on a car. Only on parts.

On the preval set up I would never try to paint an engine compartment or truck with one of those. Just get a small compressor and a touch up gun. Way better results and then you have the ability to paint everything. Using a preval you just can't get enough paint on the surface and you will have overspray lines.