Bought this Ancheer electric bike from a grad student leaving campus about a year ago.

Paid only $350 because the battery was bad.

Turns out the battery it requires is hard to find, so I purchased one that's even more powerful but it's bigger and so I had to use Velco straps to make sure it stays in place, but it makes it just a little less convenient to pop it on and off, when necessary. The battery can be locked to the bike, though.

So, asking $550 obo. It works great!

Can be seen on campus.