I'd say it's a FAIR price if it's in as good of condition as you make it sound. Keep in mind, you could feasibly get a DDR Extreme in fair condition for 2.5k, then invest another $300 or so to make it an OpenITG machine. Of course, that requires a little work and know-how, so if this guy's is in full working order and ready to go, it might be worth it. I would ask him if it's on OpenITG or not. OpenITG is definitely the way to go with these cabinets now-a-days, but putting OpenITG onto an upgradicab is sometimes tricky. For more info about installing oITG on a upgradicab, I'd check out BoxorRoxors.net.

Wow thanks for the info! Looking on ebay there are a few Extreme cabs for around 2.5k just like you said.  I know that *this* ITG machine has a ton of extra songs put onto it...permanently, not just on a usb stick like the r21 patch lets you do.  So does that make this an OpenITG machine then (is it even possible to permanently put new songs on an r21 ITG machine)? 

If it's possible to permanently add songs to an ITG2 cab...and if that's what this is then I'd probably be willing to shell out the 4k to 'own a piece of history' (own a real ITG machine), but if this just an openitg machine I'd be better off buying an extreme for <$3k and doing the install myself.

Thanks in advance for any answers, sorry I've got so many newb questions (I never thought I'd find myself in the position to buy any sort of dance game so this is all really new to me)

Yes, this is possible. We did this to our machine before OpenITG was released.

I'm not certain what you mean with this, but OpenITG doesn't necessarily make a machine "non legit". Be it OpenITG or legit r21, you could put your own songs onto it, I just know that OpenITG makes things easier to do that. As I said, for more details, I suggest you check BoxorRoxors.net to get the exact details.