If the regular, high capacity battery gets you "out there", where you run out of juice, I'm not sure what the cheaper, lower capacity battery is gonna do for ya in getting back under battery power.
The trick is to ride the bike and get a feel for real mileage numbers in each Power setting, so there will be no surprises.
As poster Honkinunit said, mainstream batteries are a considerable investment. And there are no mainstream manufacturer's batteries out there that are low in capacity. And because of that, you would be paying near a grand for a 500wh battery in those brands. 475 seems quite low, and I do question the watt hours of that battery and how far it's gonna get you away from homebase. Good luck and keep us posted as to what you do.
Btw, what kind of ebike are you getting?