though you shouldn't have any problems using cheap gun,they just don't atomize the materials as well as the high dollar guns, you can buy DeVilbiss Finishline gun from any auto paint supply store for under $100,something with 1.4-1.6 tip should work fine if you don't plan on doing any show quaity paint jobs for the rst of your life, or spend $500 for a nice gun if you plan doing more than few jobs,

just as with anything ,you get what you pay for