You get screwed either way. Buy something on amazon and it's quite likely to be just as bad, counterfeit, etc. - how many times have people complained about that?
It happens, but it's not common. Amazon lets you get stuff a generation ahead of what's in stores, which often uses better tech and fixes issues in the last generation.
When "Cheap crap" first became common 20 years ago stuff got a bit worse, but it seems to be improving.
I don't think the comment about generation ahead is relevant or true.
As a final thought, I'd say at least in a store, if you have the ability to determine if something is junk by looking and touching it, you can practice that.