Thank you for considering my observations.
There are a few more considerations though:
If you are not familar with operating an earlier camera such as a Contax-based one (that includes the pre -war and post-war Contax models, and the so-called "copies" made by Kiev Arsenal), it would be very easy to trash it due to improper handling. A new camera like the Voigtlander Bessa would be a lot more user-friendly as it is based on a tried-and-tested chassis.
In addition to that, a new camera such as the Voigtlander Bessa will carry on be supported for years to come, in terms of parts availability, and the easy access to repairers. If you have stripped a gear in a Contax it would be less convenient to say the least, and lots more expensive as the part would have to be sourced somehow.
Availability of accessories and lenses is a factor that I have outlined in an earlier post so I see no reason to repeat here.
Anyway, I see the vendor of the black Contax copy is Arax, one of the (if not "the") most respected of hot-rodders of Ukrainian cameras, so I think it should be a safer bet than the one in the UK.
Whatever your decision, I wish you good luck.