I had my Mc2100 serviced by Pat at http://classictubeaudio.com/
I had 1/4 jacks put in the unit, and the full service was $325.00. Pots were scratchy, and intermittent.
Great guy. Easy to deal with. Really knows his stuff. He has a full service classic audio shop, and prefers to work on McIntosh's.
Don't know how that compares, but my 250 will go there in a couple of months. I told him I wasn't interested in a restoration, but did want the amp 100% to spec. For example, the bottom of the 2 of the 2100 face plate is broken. Doesn't bother me at all and didn't want to pay for a new one.
Hope this helps.