If this is what I think it is, the hard drives are used data centre drives that are sold as "renewed". They wipe the drives then use manufacturer's tools to reset the clocks, effectively the same as winding back the mileage clock in a car. They are sold cheaper than new drives, but not really at a price that reflects their age and true used status.

I bought 4x 14TB drives of this type, pretty sure they were listed as new, although some show as used. 1 drive was DOA and I'm still waiting on the refund.

You can see tons of them on diskprices.com

Edit: oh wait, this is a different scam. This is like a combination of the classic size scam with the data centre scam. Fun!

It's probably related to Amazon's practice of binning all products with the same barcode together. So when someone sells something through Amazon their products get bundled with everyone else's, and when someone buys they get one from the bundle. A counterfeiter basically poisons the stock, and you end up with counterfeiters selling legit products and legit sellers selling the counterfeit ones.