Nirvana, welcome to the forum! Hobie continually makes changes to its models, but not all are apparent. A couple of these are significant. First, just for SOP, check the serial # to verify the year model (last 2 digits). If correct, you have the "V-1" Drive, which was upgraded in 2009. There is a big difference in reliability. It is possible that the seller has upgraded the Drive -- if so that is good. Look at the sprockets (where the fin rod (mast) attaches). You want to see a brass insert as seen on the right side of this pic:
The next big item is the way the Drive locks in. The '08 uses cam locks that twist to lock the Driveshaft in position. In 2009 the switched to the current "Click N Go" where the Drive drops in and locks up. This is much stronger. If this boat has the cam locks, look inside the front hatch and examine the cam columns to see if they are cracked.
Look in the drivewell for any hairline cracks. If you see any, they are almost impossible to repair adequately. If the Drive is V-1, check the masts to see if they wobble. If not, you can always upgrade later if a problem develops. You can reinforce the cam columns later as well if they crack, although it's not an easy repair. Examine the hull bottom to get an idea about how well the boat was treated -- keep in mind that a few scratches are normal and harmless.
Accessories are expensive, so if your seller is including wheels, Turbofins, etc, that makes it a better bargain. If you have further questions, don't hesitate to ask.