I too use the Contax 645 and P45+. A great combination.
On parts, well, any model will go out. We have an 8 year old thermador professional and they dont make the grills any more. Sign of the times. H1 and H2 Hasselblads are still here, but 500 and 200 are history.
There is considerable float. You are not likely to find PARTS for a prism, but you can always find a prism, or a body with prism.
Actaually, as more people defect, the pressure on parts and used reduces. I bought a second body at 1/3 the price of original.
For those who want it, it is still going to be possible to use 20 years from now, at least with some backs.
Phase doesn't have much float of anything. They are a small company and can't possibly have millions (think 4-5 models, x 4 mounts x 5 territories x 30k is 3 million dollars of useless inventory. Barely possible.)
I'm not worried. In fact, I am tempted to buy back a Kodak back for some work, and older back mounts, well, what's to wear out?
you can get a used P30+ with 2yr warranty used for 12,500!
But what am I saying. I am NOT interested in more Contaxt users. I want fewer! Less competition for replacements! LOL
regards
Victor