Unfortunately, once you start in with automotive paints, and you've made that investment in paint alone, then you start running up a bill on all the extras- Extra reducer/solvent to clean the gun, wax remover- to insure you that the $80 (if lucky) or more you've plunked down for paint doesnt fish eye or lift. Then you start second guessing the quality and type of primer, same with clear coat etc,etc,etc. Luckily I've worked for a couple of car dealerships and have managed to collect a couple of quarts of paint for cars i was working on gratis. I did have to buy primer, and overkill i went- but it was a good deal. 2 GALLONS of Crest Hi-Build with activator for 118 bucks. That primer came from the recommendation of a very good Mercedes-Benz body man. Will i ever use it all, probably not. I do have a car project also, and It is reassuring to know i can prime my house if i ever wanted to. (haha)