Needing advice from someone familiar with MVS Arcade pricing

So as the title says I'm needing some advice from someone more familiar with the pricing and value of arcade machines. Someone at our local flea market has a two-slot MVS machine they're looking to get rid of at $550. The machine works well, though he did tell me it wasn't working when he first got it and needed some "tinkering." It's also missing the front keys. It currently has Metal Slug and Samurai Showdown 3 in it, which he said were included. The cabinet itself is somewhat worn as is to be expected, but not in terrible condition. One of the side vinyl decals will need to be replaced, maybe both, but the marquee is in good shape.

I've been semi-interested in getting an MVS for a while, and this seems like a solid deal from what limited price info I can find, I just would like an opinion from someone who is a little more versed.

I bought my machine new for $1,600 and I think it has 60 games. I did a lot of research and found a lot of information. If you want the machine to look like new; consider price to refurbish. I would be concerned that “it was not working when he first got it.”[attachment=28853:1DE5623E-9426-4CAC-ACED-E53DDAD91997.jpeg][attachment=28854:A8540D1C-10D4-449A-B6BC-35640D95661F.jpeg]

I got my 6 slot MVS over 5 years ago. When I was researching on pricing I came across other collectors on KLOV saying about $100 per slot is where you want to be at. Then add on the price of the games that come with the arcade. Granted this was a while ago so $100/slot might be out of date. I would get more of the history of the machine before even considering. Have him open it up front or back. Also swap the carts if you can. I can try to answer any other questions you might have. Good luck Neo Geo is the best!