The basic mechanical systems are readily available. Water pumps, alternators, AC compressors etc.
Things that are hard to find are unique Solstice parts like the rubber seals, anything to do with the top, the tulip flaps, things like cables and electrical assemblies unique to the car.
in the main, the NA is very reliable. many are used as daily drivers and are still going strong after 15 years. Fun cars that just keep going.
If the price fits your ability to pay and you think you are getting value for your money, then go for it. Life is too short. And there are a lot of "used" used kappas out there. If you find a good one and you like it and its in your price range, negotiate as much as you feel comfortable and buy it.
Tulip flaps need to be in good condition and working well
the water pump should be good to go, but can cost $1000 to change at the dealer
Clutch in good condition, changing the clutch at the dealer can run $1300