Actually, the real cost comes from batteries. They're only good for a finite number of cycles, and under the high loads they'll experience in this sort of appl

Actually, the real cost comes from batteries. They're only good for a finite number of cycles, and under the high loads they'll experience in this sort of application, I would put that number at around 250-750 flights. So if you're spending $30-$50 a battery, that adds up pretty quickly. Electricity is really cheap in comparison.