So I went and looked at the Ikari Warriors and Shinobi tonight. This was my first experience looking into buying some real games.
Shinobi: was in an old Stargate cab. you could see the old design on the side of the cab. The monitor was burned badly IMO. the EBAY ad said NO burn-in.

It was also a vertical monitor turned horizontal so the burn-in was sideways (different game..couldn't make it out). The power supply was a new 'switched' power supply. I wasn't looking for authenticity on this one and I don't know the first thing asbout the old transformer power supplies or the new switched power supplies. it was a Jamma board. The cab was painted black and IMO sorta decent shape but chipped on the edges here and there. the T-molding was not in the best shape. The buttons were bleached out and cracked. The control panel was slapped in and cracked as well. The joystick was really loose and an 8 way which i'm sure was wrong for the game. The Joystick was stubby and had a really thick shaft. overall i thought the cab was ugly, but it did work correctly.
Ikari Warriors: This is why I went out there. The monitor had no burn in. The controls were worn but worked correctly. It looked like the original cab, or a well done conversion. It was painted black but had the side art and marquee. It had no bezel, but the glass was there. The cab itself had a large chip in the back edge near the top that someone just painted over. The bottom had water damage all around and was flaking apart. The T-molding actually had screws holding it to the bottom. Inside there was a hole in the bottom from water damage/rot that was the size of a half dollar and larger where the wood was partially gone. The coin mech was finicky, but would work. Not in as great of shape as I expected.
In the end I offered him $350.oo for both then $375.oo but he said no to both offers. he did show me his 'keepers' which were nice. Had some stuff I wish i could get, plus a nice 2 player mame machine.

I didn't buy them, but i think I'd be kicking myself if I paid over $375.oo for both. Being my first experience i am wondering how typical this was. You can see his EBAY auction link about 3 replies above this.
I am hoping I can get some cabs at the next Super Auctions in Long beach this october. I wouldn't mind paying a little more for cabs in better shape.
Please chime in with your opinions!
edit: it says "sold" on his auction, but it isn't...

Ikari Warriors:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3237351435&category=13716 Shinobi:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=13716&item=3237393991