Please correct me if I am wrong here, since I am not an Insight owner. I have this notion in my head that the Insight battery is not protected to the same degree as the Prius against deep discharges, and so my have a shorter lifespan. It was mostly this consideration that would make me shy away from second hand ownership, especially if the car was used by multiple drivers may not have cared much about how they drove and it's effect on the car's longevity.