[CC69Rat]

I don't do it for a living, I just do a Fender or hood occasionally. I don't have a shop or booth

But, ask 10 people you'll get 10 different variations. Jim is the man though.

Just me personally I work the metal, sand at 36/80. Apply a skim of filler. And as he said get the filler as flat as you can and get it close. 80, then again at 180 will get you there. Epoxy primer, then 2K primer within 7 days. 220, 320 block and guide. Final prime and block to around 600. Especially if you'll be using a metallic base, or the metallic will settle in the sand scratches and you'll see your body work. If you're using a single stage non metallic urethane (?) I'd probably go to 600 to be sure but 500 (imo) would work. Final sealer, base, clear, cut and buff.

It's a lot of work.. and why body shops charge what they charge. The tools, materials are not cheap and very important to a high quality result. You're right though,after you add everything together it makes that 6-7k paint job seem a little easier to swallow.