Some dude listed his non-working Baby Pac for $400 on my local CL. Sure, the thing looks absolutely pristine, but non-working? There could be ALOT of problems with a game like this. Needless to say, this thing has been sitting for like two weeks untouched.
If it were working, I'd say my local one would be a steal at $400, but should go for as high as $700-$800 to a die-hard collector. I believe oregonarcade picked up his working one up about a year ago for $400-$500.