Korg 2600 - ~ €1000 Behringer 2600 - €300
CZ Series doesn't have much cachet simply because phase distortion synthesis was the 'we have FM Synthesis at home' cheap alternative to 4 OP FM Synthesis in the 80s. About the only USP they have in that arena is the fact they're responsible for the 'Reese Bass' sound - the 'Wilhelm Scream' of Techno if you will.
They refurbed their Chinese on OTOH.
It's not quite in the ball park of something like the DX 7 or several of the better known analog synths, which have nearly all seen re-issues, mini-versions, software emulations, etc., often several. Damned near every Roland synth from that era has seen a re-issue and official plugin. Yamaha has been more measured in their re-issue plays, but the DX did get a reface DX, along with the CS, CP and YC. FM synthesis has been wildly successful in nostalgia synths as well as novel takes on the idea (e.g. the Elektron FM groove box) and Korg's Opsix (I have two of them, the first gen small one and the big expensive one made in Japan), and Yamaha still ships FM synthesis engines in their high end workstations. And, there's at least four plugins that emulate the CZ (I'm working on a fifth to be released in another month or two).
I don't think all that would exist without some demand. I have a soft spot for early digital synths, and I think a lot of other folks do, too. I don't like to buy from Behringer, but it's the only hardware option out there right now aside from the real thing (I own a real CZ 101, but I wouldn't want to take it out of the studio).
AudioPilz (Bad Gear) even made a video demanding it: https://www.youtube.com/watch?v=Kb8nMZE-bb0
I have a Casio CZ-5000, the 61 key version with sequencer. It’s well made but given its age I’m not sure I’d want to take that to a gig either.
That you can buy them on ebay all day long for less than most cheap synths costs new argues against it being viable.
Edit: But also, the CZ was generally more comparable to lower-end DX synths, like the DX27 or DX9. It was a budget synth in its day, while the DX7 was the pinnacle of digital synthesis for at least a year or two after release, everyone had to have one.
There's also a "Always wanted this, can finally afford it now that I'm rich" niche for the high-end remakes from Korg and occasionally Moog etc.
There isn't a huge "Bought this forty years ago because I couldn't afford anything better and would quite like a modern remake" segment.
Casio do still make pianos and Casiotone keys which include samples and some CZ and VZ series sounds. (I don't know if they're sampled or DSP.)
Korg does put out "nostalgic" remakes of analog synths just as well: MS-20 (complete with patch board), Arp 2600, as well as digital versions like the Korg multi/poly virtual analog.