I recently purchased a demo ST from B&H. It looked ok except for the bottom plate, which was disproportionately well worn. I say "disproportionate" because the rest of body seemed pretty good. It looked as if somebody took a worn bottom plate off from another ST and stuck it in there. It also came without the eyecup.
Anyway, that ST had a problem with aperture setting and rewinding. So I sent it back to B&H and they said it could be repaired at Contax or I could get my money back. Having been disheartened by the whole experience, I opted for a refund.
But now I see another demo ST on B&H, with the same SKU#. Is this the same camera or not? If the same one, how could it be repaired so quickly?
Anyway, what my experience has taught me is that being a "demo" from B&H has no direct bearing on the condition of the item on sale. It simply means that the camera was used as a demonstration model. How abused it was cannot be told, and one must assume that the condition of a "demo" camera from B&H could range from virtually new to pretty well beaten up.
I am not criticizing B&H per se, as my dealings with them have been generally positive. But it does make me think twice before jumping on another demo Contax camera from them.