There is a Chinese store here that sells electric bikes. The cheapest is $400 and it comes with a spare battery. As per the blurb in the poster, you don't need to register it because it is not a motorcycle and, take note of this, you need no helmet because it is just a bicycle. Get that? Helmets for bikers are not compulsory here. As with the motorbike, since I the swelling on my leg prevents me to buy a new bike, I am contemplating on getting an electric bike.