Need just the console itself because you've already got a controller and hookups? ...not to mention hookups for the 3DO are really easy - just a composite video cord! Anyway, pick one of these up, and you can get to playing - they might have flaws, but they work perfectly!
NOTE: All photos depict good condition items only; actual product may vary.
Used FZ-1 Console CORE [taped power cord] (poor condition)
Used FZ-1 Console CORE [cd cover missing] (poor condition)