I recently saw the Red Sound Darkstar listed in Musician's Friend catalog. Curiousity led me to explore the mp3 files, and check out the deja.com references to it.
It's currently being offered @ $379 (US), and has some merit to it. For arranger / composers who need a little analog oomph, this might be a horse of a different - but interesting - color.
see: http://www.redsound.com
For one with $49 Vocoda expansion tossed in: http://novamusik.safeshopper.com