The 501CM/503CW are premium priced at the moment, a number of "in" photographers with influential blogs have abandoned the Contax 645 as the road to nirvana and embraced Hasselblad, thankfully they require you use the 80mm lens exclusively (wide open of course) so lens prices, avoiding the CFE series which are popular separately as a bargain lens on the H series via the adapter, have not followed them.
Given a print or scan I would give myself a 50/50 chance of identifying the C or CT* or CFE lens I used, and don't ask why I have the same focal length in all flavours in some cases (including an 80 and 150 in HC but they don't count even though I shoot film on the H1 and it is handy being able to mount any 500 series lens.)
Yes sorry that back isn't film it's that other thing and works perfectly well with the C lens.