Hands down the best ebike company around is Luna Cycle :Luna Cycle LLC great products, the absolute lowest prices, cutting edge batteries, and great support and service from an American company. This means cheap shipping costs and easy warranty support from within the USA.
If you can work on your own bike at home you can build an ebike as good or better than the $4000 factory bikes with a much longer range and more power for less than 1/2 the cost. You already have at least one and probably two old MTBs in the garage, why not convert one and see if you like it before dropping the cost of a decent used car on a low power Bosch bike?
I would avoid HPC High Power Cycles sold me a new BMC motor it was DOA been trying to get it fixed from then back n forth sending it to them its there now again. Wish I had never heard of them . Paul from EMV3 is good n cheap but hes in China , Have heard good things about Luna cycles