At that mileage, I guess it could go either way. Properly cared for, it might be a good car, but if it wasn't maintained, it could be a mess. And being sold by non-MB people, I am sure you'd get some funny stories about it. It doesn't look bad, though.
I've never done a carfax on my car. The car was one owner before me, and they kept every receipt. If it got crashed, they sure fixed it perfectly, and the owners kept no records of it. I'll risk it.
Here's a lovely late 126 from ebay. It's my color, and the condition looks fantastic. Certainly worth it.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2448484057&category=6332