Lets be realistic, a decent battery from Luna cycles is going to cost between $450 and $600 at your door (including shipping and charger). And they are one of the best priced vendors out there.

And yep, I bought decent inexpensive battery from china once - it lasted about 2 years of light usage. I'm sticking with the more expensive name brands now - Panasonic or Samsung.

Batteries is where your cost is. The motors and controllers are cheap relative to that. Companies like Bafang and Cute make good geared hub motors (or mid drive) that are quite reliable and well proven world wide.

I'm not a fan of direct drive, the light weight and free wheeling capabilities of a geared motor are fine if you don't go much over 1000 watts.