Jack Bros is worth a heft chunk of change on it's own at this point so I'd at least sell that separately if you wanted to get the most out of it.

I can't give you a solid price since I just got my Virtual Boy recently and am trying to figure out pricing too, but I picked up my VB in a Blockbuster case with 2 games for $40, but I'm betting you could probably get a good $60-$70 for just your unit and case together if it still works properly.