For those that would ride an Ebike. It's battery cost. Getting the whole kit to cost less than $500 is key, but not by providing sla's. Once gas is 4-5 bucks again though, then lithium looks cheap even at todays price. Funny thing is, gas, even at 4 bucks, is insignificant when adding up the real cost per mile of a car. Even the $3,000 ebike comes in as cheap as a small motorcycle, but the motorcycle is usually faster.
The trouble is, bike riders are comparing the cost to pedaling a bike, which is sort of free. Actually, food is more costly than charging a bike, but hey, you are eating it anyway, and more tastes good if you pedal it off.
For most people though, it's the little things that stop them. Little cement trucks, humvees, 4 cab pickups, that try to kill em daily if they ride a bike. Same stuff that keeps em from riding a 150cc scooter or motorcycle. Yesterday a one ton truck ran a stop sign on me. Suddenly there I was yelling at him through the drivers window as I passed him.
They don't expect 30 mph out of a bike, so you better be ready for THEM.
Then there's the fact that work is at least 15 miles away, weather is perfect for a bike only 6 months of the year, hard to carry stuff, commute time doubles, etc etc. At least in the typical US city of more than 50,000 people.
For me the ebike hobby is almost free, since I put ten bucks in my pocket every day I ride to work. Free motors for reviews doesn't hurt any either!