I dropped mine off with a Mancini race rebuild kit and it cost me $300 for labor. Everything was tank cleaned and it looked like a new one with its fresh paint when I picked it up. I've never done one myself but I could easily see 4-5 hours for what I got so the $300 seemed more than fair. $5-600 complete with warranty seems decent at least for my part of the world where door rates are $75-$100/hr.

Kevin