I always believe in paying a workman for his labor, especially moreso if the guy is an artist.
So if a service is $100 and it takes 4 hours to get it apart, ultrasonically cleaned, inspected, oiled, reassembled, checked on a timer for beat... that's a lousy $25/hour.
An artist is worth far more than that, and I personally wouldn't want someone tearing my vintage gen down and slapping it back together in 4 hours.
I have a carefully constructed mental image of Ziggy sitting in a warm wooded den, tools askance, briar pipe nearby with a snifter of good brandy, Debussy on the stereo, all dressed in tweed and slippers, J purring on the couch, and he's inspecting each minute detail of my watches with the biggest magnifying lens you've ever seen. After each successful inspection he dips the part, one at a time, into a vat of cleaning solution, and carefully hand dries it, placing it carefully on a padded velvet cushion. Of course he changes the solution between each part.
See? That's how an artist does it... honest. Just ask J. And the results are well worth the going price.