Thanks Birna and Fons.
Special lenses indeed and prices go up. One of the reasons is that these lenses work excellent on mirrorless camera's. Another reason is that it is increasingly difficult to find a mint copy.
My current sample is a mint one in the Canon FD- mount, and had a low price because of that mount, I guess. Works perfectly with the FD-Z adapter on the Z's.
The Ai-S 35-70/2.5-3.3 Angenieux is optically much better than the more 'flat' AF-D 28-70/2.6 version where compromises were made because of the AF construction and the fixed f/2.6, Especially wide open the difference is evident.