You could take a look @ the Future Retro stuff. He was the first to really revive things with the Mobius, then later came out with the Orb sequencer.. which you can get 400-500 used if you are patient. Unfortunately, the Orb is only 1V/oct, while the Mobius had both (Hz/V and 1V/oct).. which is one of the reasons why the Mobius is so expensive still second hand. I haven't looked @ the market in awhile though, last I looked most other options ran up into the $1K price range... I'm sure there are quite a few available now. For Korg and old Yamaha owners though, most will probably require a Hz/V convertor. I'm keeping hope that Korg is going to release a new SQ-10.
I've always fancied to have one of these, but I can't justify it:
http://www.analoguesolutions.org.uk/con ... erkorn.htm
or:
http://www.sequentix.com/cirklon.htm (like 1.4k USD though with the CVIO option)
no way around it, decent cv step sequencers are pricey.... look to spend 500-1200 easy.
A better option might just be a midi to cv convertor and sequence from your computer. That's another reason I like the Mobius, I use it more as a midi to cv convertor than anything anymore.
If Korg came out with an affordable sequencer it would blow ppls minds. It's clearly within their grasp if they chose to do so.