That's not even true for normal bicycles. Serious cyclists can spend massive amounts of cash on their rides.
Aside from that, if you're using this as a vehicle you want more than just the cheapest thing out there. Reliability and serviceability are important when not having the bike means you can't get to work or your kid's school.
True, but this bike is completely non-standard so sort of blows that. There isn't even a direct connection between the pedals and the wheels. If the electrical bits stop responding you don't even have a bike, you have a really awkward velocipede. Every other e-bike that I have ridden or seen is still a bike when there is no power.
Most serious bicyclists I know, some with wonderful bikes, still spent less on their bikes than the typical American spends getting the air conditioned seats option in their F-150.