I have to say that I'm one of the few Ebay success stories. Found my 95 C220 on Ebay after it failed to hit the reserve. 58,000 miles, with a cracked rear bumper cover (no metal or frame damage whatsoever-- Got it replaced, looks sweet now.)
Had it checked out by a mechanic, closed the deal for under $9,400. It had just had the 60,000 service done by a dealer, with a new battery and a couple of other things for the princely sum of $1,250. Drove it on a roundtrip cross country road trip (MB's are wonderful highway cars), and now, with 74,000 on the clock, I'm looking forward to the next 74,000 with this car.
Have been a bit of a maintenance freak, synthetic oil and OEM filter every 2,500, air filters every 6,000, P/S filter and fluid, Tranny fluid, cabin filter once each.
So, I got lucky with the first MB I ever looked at or drove, but keep at it, it's worth it. And to think that I almost bought a used Camry instead....