Be careful when you buy from Amazon and especially ebay. They might send you a refurbished drive and you may never know. If you do buy from Amazon, buy directly from Amazon and not a third party seller.
I bought my first WD101PURZ (10TB Purple) directly from Western Digital in September 2018 for $340 +tax. Build date 9 JUN 2018.
Bought the second one from Amazon (sold by Platinum Micro, Inc) in July 2019 for $267 +tax. Build date 16 NOV 2018.
Bought the third one from Amazon (also sold by Platinum Micro, Inc) in May of 2020 for $252 +tax. Build date 27 DEC 2019.
All three came in the same type box packed the same way. No issues with any of them.
Bought three WD40EZRZ 4 TB Blue drives, one from Newegg and two from Amazon back in mid 2019. All three came in the same type box an packed the same way. No issues for any of them.
Bought a WD 500GB SSD from Newegg. No issues.
I get all my drives from amazon as well. No issues so far. Also, only get a purple drive. Don’t use anything else, including red’s. Purple is specifically for surveillance for a reason!