I am a bit confused, When you buy from Amazon, isn’t there an explicit indication whether you are buying from Amazon itself vs “marketplace” seller? Shouldn’t stuff direct from Amazon be legit?
A recent example is Eclipse glasses that were purchased on Amazon. Since the inventory was co-mingled and Amazon doesn't have the time or expertise they refunded most purchases of the glasses both from legitimate and illegitimate sellers.
Go to Youtube and search for "chaseontwowheels" and "rocks", you'll see an interesting story in three parts about a guy trying to order a high end camera from Amazon.