Hmm...
Here's a high-miler in PA:
http://cgi.ebay.com/ebaymotors/96-E300D-E300-300-DIESEL-HIGHWAY-MILES-WELL-MAINTAINED_W0QQitemZ270026037014QQihZ017QQcategory Z6335QQrdZ1QQcmdZViewItem
Although I'd question the reliability of the dealer:
"This vehicle needs nothing and is ready for the cross-country trip home."
Look at the tires!
Anyway, hopefully someone can chime in with their experiences.
Freybird; Is the 87 a 5 or 6 cylinder? My father has an 83 300sd and it's been a great car. I've done some work on it and really enjoyed it... nicely laid out, quality materials and good engineering. Plus, parts weren't really that much more than VW, which surprised me.
Porsche virgin, thanks for the link. I've spent some time lurking over there in the past. Lots of knowledge, but they seem SO partial to the make that it's hard to tell how objective they are.