I think Delano and others speak the truth. Look at it this way. What is the monthly note on a new vehicle. If you're shopping for something of MB quality you'll easily spend $500 per month or more.

You should easily be able to get the head R&R'd for less than $3K, but let's say it was $3K including the work on the seal. That is only 6 months payment on a new sled.

If the trans is working well now, change the fluid and carry on. Chances are it will last at least until 300K. I have 308K on the trans of my '95 E300D, works just fine.

If you like the car, as others say, find a good indy shop and fix it, IMHO.

Rgds,
Chris W.