Heck, buying a used car, no matter the make or model, will always be a crap shoot. Manufacturers, as best I understand it, are only obligated to keep a stock of repair parts for 10 years. With all the electronics in vehicles these days, it's not like any shade tree mechanic can fix all of the problems that can show up. And lord only knows I don't have much faith in ANY so called "vette techs" out there that I have had contacts with.
You may want to research some of the electronics parts for that year and model and just do a quick search to see if they are still readily available. Things like the BCM and ECM, for instance. But even minor things like door lock modules and the numerous engine sensors will eventually get hard to find.
These same thoughts run through my mind with my C5Z. I guess there are things on that which could break that I would not be able to find a replacement for.
So if you can, get at least some sort of minimum warranty on it, just in case. If they are selling it "as is" you will just have to take your chances. At the very least, have it checked out by someone who can view the history codes to see if it is flagging any errors. From what I understand, you can't just view codes through the DIC like you could with the C5s. So you need a reader, or someone who has one.
Plus it would be worthwhile getting any used vehicle up on a lift to have someone competent to check it out for obvious things like fluid leaks and stuff. And something like rodent damage to wires in a vehicle being parked outside could cause you uncountable headaches.
Sorry, but damn I sound negative lately......
Wish you luck.....