Cost of a single-color paint job?

Well, I checked with my paint dealer today; I can get Nason (DuPont) acrylic enamel in Winchester Gray for $126.00 per gallon (plus hardener & reducer) and he says it requires no basecoat or clearcoat.....prime & shoot. I'm gonna start out with a quart of color (in the spring, when it's a roller again) and shoot the engine bay for starters...that will tell me if I can handle the rest.