Wow, at 700$ for a low mileage car, 10mpg isn't a problem. If I ever get to do that US road trip vacation, I'm going to need some advice on how to find these...
Mine'll get about 20MPG at 80mph on the highway with the A/C on, and more like 15MPG in town (worse if there's a lot of idling or A/C usage or both). The '94-96 models have a detuned Corvette LT1 engine in them, and have more power (260hp vs the 180hp in mine) and I believe better mileage as well.
It's a great road trip car. I live in the Chicago area and we've taken it all over. Texas, Georgia, New England, Kentucky, northern Michigan, etc. all without worry. It handled driving ~1600 miles straight (in 18 hours) home from Texas better than I did. It might be taking us to the west coast in a few months.
It seats seven, comfortably. It also fits a metric fuckton of cargo. We have had four dog crates set up in it with room to spare at the back for a cooler. It fits a 4x8 sheet of plywood flat. I recently loaded 1000lbs+ of sod into the back. I once fit a queen mattress inside. I've strapped two queen mattresses on top of each other to the roof (for all of three miles). I've strapped a bigass couch on top and driven at near highway speeds (~45mph). A cooler survived strapped to the top driving 75-80mph (but lowered MPG a bit) for a few thousand miles.
It also has a tow hitch, and has some ludicrous towing capacity (I want to say 5000-6000lbs), but I haven't used that. The previous owner used it to haul his boat.
It's basically a pickup truck pretending to be a station wagon. Except that you're not way up in the air, and you have a reasonable center of gravity.
The A/C sucks on a hot day and is required with any sunny day above ~60F, but that's mostly a consequence of the car having so many giant windows that it turns into a greenhouse. Tinted windows would probably solve that, but I haven't done it.
$700 isn't exactly a typical price. We bought it in summer 2014 before gas prices went down, plus we bought from a recently-divorced guy in an upscale area of an upscale town that needed it out of his driveway more than he needed the money. But you can still find them around $1500 or so around here in decent shape. "Collector" grade ones go for ten times than on eBay, but I got this car to drive, not to look pretty.
It's only had one "old car problem." It sprung an oil leak at one point. Beyond that, it's put up with smashing into a deer in the middle of the night on a country road in Indiana (minor hood damage, needed new driver window glass and driver-side headlight) and having something on a Michigan road blow a three-inch hole in the gas tank. It's held up like a champ.
