To me, it's priced high. (As I had my 2.5 B6 priced too high earlier this year but have now decided to keep her)
A lot of people are put off the 2.5 due to the known issues, albeit, it seems you have tackled the cams already. Fuel pumps are another common failure and can be expensive if you don't have the know-how and VCDS for coding etc. (Unless it's a virgin ecu).
Rust on the rear arch hinders the price too a bit imo.
I am one of the watchers and I have been for a little while, a bit before you posted it on here.
It's one of those sales where you need to get a person looking for that car with that spec I'm afraid. It will sell at some point, but it won't be overnight.
My old man has a mint, low mileage S8 D2 for sale, had it up just over a year and took it off as there was just no genuine interest.
Good luck with the sale. Time is your best friend here I believe......
Dan