I don't buy or sell Leica equipment, so definitely not an expert.
But KEH has one for sale now for US$2469
Do you have one? If you have or could take a photo of yours, I'd love to add it to the camera database at
http://www.pbase.com/cameras/leitz/35_2_summicron
If you feel like it, send it to
slug@pbase.com or if it's on PBase already, let me know.
I have photos of the bayonet mount version, but not the screw mount.
By the way, just added a lot of Leica photos yesterday at
http://www.pbase.com/camera/leitz
Still have a lot of work to do on the lenses.
-slug