eBikeling's initial offerings were relatively small geared kits for about $175. They have increased their product range recently and the latest "3000w" (50+mph) kit is <$600. They also have batteries to 72V, so with the 60 amp controller in the 3K kit, sounds more like 4K+ (forgetting about efficiency since AFAIK everyone else does too). Too big for me as 33-35 mph is about my limit on an ebike.

It's probably hard for ebikeling to compute in the small 500w motor market with similar offerings from chinese vendors at a lower price. That would explain these super big motors.

My origiinal ebike conversion will be a 500W 36V rear hub ebikeling kit that will be 10 years old this summer, I [aid about $220 USD for it, but the price dropped quick, as my second one was about $175 a year or two later.

I had a 1000w front direct drive system on a cruiser that was too heavy and influenced steering (although the kit worked perfectly), so I went back to a smaller motor.