These frames seem to rust easily - my 09 LTZ had some frame rust, driveshaft rust, steering knuckle rust, etc. It wasn't even in a terribly snowy, salty area - PO lived in southern Utah. All surface rust fortunately, and some day I plan to get underneath with a wire wheel, knock the rust off, and put on some undercoating.
Like Bigbeard said, you can get the 12v covers cheap on Ebay. This is another common problem, along with the HVAC buttons rubbing off. I bet the dealer will knock off $100-200 for this if you mention it and you can probably replace all the covers for under $30.
To reupholster leather you're talking big money, but leather seat covers can run anywhere from $100-350 (per row) depending on quality. It looks like the cracks haven't turned into full on rips yet, so that's good, and if I owned it I would definitely condition the leather and then put a cover over it.
Mine also developed a squeak 1000 miles after I bought it. Turned out to be the belt (but I did replace the tensioner and idler pullies first chasing it).
The price is right, and I say if you can deal with not having Nav, moonroof, bluetooth, and cooled seats it would be a good buy.