I can't speak specifically to the 05 Tiburon, but my experience overall with Hyundai has been very good in regards to reliability. I've had an 01 Accent, 01 Tiburon, 03 Elantra GT, 08 Accent, and now my 08 Tiburon. All have been outstanding.
The price on the one you're looking at seems okay. It all depends on the condition of the car. You'll need to keep in mind though that the timing belt will be due for replacement at 60k miles or you'll risk doing extensive damage to your engine if the belt fails. That's normal maintenance on the 2.7L V6. I don't know what the replacement cost is, but you can check with your local Hyundai dealer or a reputable shop in your area.