At that price, you can buy without concern, because you are almost guaranteed to be able to resell it for the same.
I had a copy of the ZF2 25/2 Distagon for about two years. I believe my copy was a good one. It was an excellent, very highly corrected lens. It had even sharpness across the frame from wide open. Relatively small amount of regular, non-wave distortion, so many shots of the man-made environment appear to have no distortion at all. Reduced lateral CA compared to Zeiss 35/2, 28/2, maybe even less than 21/2.8. I found it slightly more difficult to focus(at wide open) on the D800 screen than the 35/2, 21/2.8, etc.
Wide open at infinity it seems very slightly less contrasty on the distant subjects than it does in the medium and close range....many users have reported this phenomenon.
I might re-acquire this lens if it was offered at such a reasonable price.
I could post some shots I made with it if it would be useful.