What did he quote to paint the tank and covers? Is this including prepping the surfaces? You can save some money by prepping it yourself and having any holes masked off so he just has to hang it in the booth.
Spraying a real tricoat isn't as hard as everyone makes it out to be, unless you're trying to blend. Since you're respraying... if you want to do it yourself with an HVLP gun at 20-30PSI do some spray patterns (look online at how to do this) at 6-10 inches away. Once you're satisfied spray your sealer, wait for it to flash off. Spray your base like you normally would, the second coat for the metallic spray at 6-10 inches, then do a second coat (while still wet) at 12-18 inches, then finally a third coat at about 24 inches away while wet. Don't go crazy, the second and third wet coats are to help the metallic lay out evenly. Do the same thing for the candy clear coat.
That's a general guideline, you can get some spray-out cards and test how many coats for the mid and final coat. Be certain to use the proper sealer colour that is recommended by the paint vendor. Don't just spray generic "mid" gray if it does not call for it.
Also, does your painter specialize in hand painting pin stripes? If not, don't use him to do the stripes as there may be rework or overspray, etc. If you must have the stripes cleared over then it may make sense to have it sprayed minus the final clear coat, then lightly scuff the surface with gray scotch brite after it flashes and have someone who specializes in hand pinstripes do it within the next 24 hours. Check with your paint supplier, but usually its about 24 hours in between base and clear coat for modern stuff. After the pin striping has dried, again do a light gray scotch brite over it and then finally do your clear. However, for all that work, I'd rather spend the $100 on the decal, clear over the decal in the booth (with gray scotch brite of course).
