Check here:
http://www.mercedesforum.com/m_95189/tm.htm

As for mileage that is a little high but if it's a one owner you can talk to them about the kind of miles.
Short trip, stop/go = keep looking Highway miles = maybe OK.
Based on what I've seen $10-11K sounds about right if the interior and paint are
nearly perfect and every feature works as it should. 4MATIC is reliable but I would buy 4MATIC only if I needed it because you'll pay a premium (up to $1K over RWD). If you don't you're just dragging around 100# of steel and paying $3.50/gal for the priviledge.

If the motor has been well serviced with Mobil 1 Syn and fleece filters per MB, it'll last a long time.

Take your time and shop around. The E320 was a popular car and there are many good ones to choose from. You can get lots of tips on what to look for from these forums. For the 2000 you want the W210 subforums which is the chassis model for your car.

When you find one you think is a good deal have it inspected by a competent MB mechanic. It may cost a few dollars but major repairs done by the dealer are VERY expensive.

Good luck.