Depends on the lens. If it has a Color-Skopar, it's likely to sell for $400-500. I think I paid $650 for mine with the Color-Heliar and sold it to some nutty collector for around $1100. A Bessa II with an Apo-Lanthar and 645 mask can go for $3500-5000.
While I had one, I thought the Bessa II with Color-Heliar was a great camera, but the ergonomics just didn't work for me. It's kind of a left-handed camera.