Depending on the market where you are I'd think they should go for 150-250 bucks in that condition. If you added a marquee and got the light working it would go up a little. The only think that was MAMEd on that thing is the track ball. If you want just get some new art and new glass you'll be okay.
Get a JAMMA Harness and a Kick Harness and a copy of Marvel V Capcom of SSF3 or something and it would go for about 500 I'd think. Maybe more, I've seen them for for insane amounts online, but it really depends on if you find a good buyer.