[AgentX]

The CV 50/2.5 is no longer manufactured. The only ones available are either second hand (which doesn't often happen as people like them so much they hang onto them) or PhotoVillage in new York are still advertising new ones. I think I saw they had 4 or 5 left in stock and when they're gone, they're gone. There ain't no more! They only have them in silver. I bought their last black one some considerable time ago.

Bryce, you probably saw my thread on RFF, but I just grabbed what I think was the last one at B&H for cheap. Actually had it in my cart, took an overnight to think about it, and it had disappeared in the morning and was showing out-of-stock. The next day, however, there was one in stock again somewhat miraculously, so I jumped on it.

There was a sub-$400 one on Ebay (new) that seems to have disappeared, so PhotoVillage at $400+ seems like your only option for a new one, and not many seem to come up used at this point. CameraQuest has them for $599 in both black and silver, and seem like the best place for product support (and sincerity/enthusiasm; alas, I went for price, and took a risk on support.)

You might get best bang-for-the buck looking at a Canon leica threadmount lens, or an older Elmar 2.8 in good shape.

Maybe try emailing Sherry Krauter (google her site) and see what she has in stock in threadmount. She's a noted repair tech who sometimes has a small stock of lenses. Her online inventory is very out-of-date, however.