I usually try and at least look on other sites first, Amazon's prices aren't necessarily the best (in fact it's usually guaranteed that they aren't) and it's hard to know what you're getting. For somethings though it's fine like phone cases etc; stuff you would kind of expect to be garbage anyways and it's often hard to find the exact things in a local store.

There's just enough ok shows on Prime to watch as well, it's like they know exactly what they can get away with.

(Now their stack tv in Canada is basically useless garbage, page after page of episodes that "aren't available right now"...so why show them then)