We stopped buying drives from Amazon when we got drives for "the wrong region" and couldn't RMA them. NewEgg is a bit better, but don't buy refurbished drives. Provantage is another reputable vendor that usually has decent prices. If you're local to the SF bay area, check out Central Computers. King Star USA also works if you're a business customer making a large purchase.
There's been oh-so-many reports that even if you're buying from the official store of any known brand, with FBA, then you might as well still receive a knock-off, due to the inventory co-mingling issue. Have they ever resolved this for good, or is noone really bothers to even pay any attention to this anymore?