I know that guy..
Both websites are same guy.
He had bought a warehouse's inventory of electric bikes for pennies on the dollar.
He put them on eBay for 350 a piece, no one bought them, sold a bunch locally for $450 so then he put them on those websites for $600 including shipping.
There is a warehouse in China that makes those and sells them for 250usd not including shipping.. Shipping by boat is $120 USD (2 month delivery time minus batteries, or 186usd shipping for two week delivery by air.
You can have them shipped to your house for $436usd arriving in 2 weeks.
Mind you, none of them have batteries but the ones he sells, but they can be had for under $100 on eBay.
(FYI. he has them listed in alibaba for $350, but he's never answered my emails to him through alibaba.)