Aside from the "cost of my time" (er, retired, so since the money is coming in anyway, I'm not giving up time at work in order to work on my skis, so probably a zero there), just knowing WHAT WAS DONE to my skis and seeing the impact is worth it. Saves me bringing things back and yelling, as well. I'm believe once you leave the skis with the guy, you really have no idea what they are doing, they could be doing what you tell them or ignoring that and doing what they want to do. Yes, there are good tuning guys out there, but is the guy you had the long discussion with the actual guy doing the work? You'd be having to hang around and watch. Which is fine for some things and some times, but as a routine is rarely possible. Just easier to do things myself.