Its not worth 10k, but that doesn't mean the car is not worth keeping as long as everything else is in pretty good working condition.
Your issue requires complete transmission removal. Unfortunately no way around it.
Read here on what you need:
http://www.w124-zone.com/articles.php?article_id=21
You'll find the front pump has considerable pressure loss, or the b3 disks are worn like so:
I personally only had the 1st and the rest were like brand new, but its all dependent on fluid change history and driving habits. This was at 100k miles.