The problem is, it'd be trivial for someone with a sticker printer to slam a new label on the drive, saying 16TB. It'd be quite unrealistic to have Amazon own the tools and perform QA testing on all the millions of items on their site. You see a similar problem with knock off headphones, even plugging them in and listening to a song wouldn't be enough to find most fakes.
I think the only real solution is this to be fixed at the government level. At the moment it's too expensive and risky to go after customers, even when Amazon can determine they are running this scam. Either you get drawn into a legal battle trying to prove it, or you get labeled as evil Amazon going after the innocent little guy in the media. It's easiest for Amazon to just raise prices 1% and call it a day. Which is what Walmart does for theft/return fraud as well, and likely every company in the U.S.
There needs to be a law that makes it easy for Amazon (and other companies) to go "this account was found to have returned different merchandise 5 times, they need to pay $xxxx fine" and it to be done. But if even if one of these cases go to trial, it'd be at least a $5000 expense to Amazon.
As long as this is impossible in our legal system, these scammers will continue to thrive.