Beware MDD at the top is alleged to sell drives they’ve refurbished which are essentially used but with wiped smart. Other cheap deals… check sellers. If it’s not sold and shipped by Amazon it could be slightly used drives (usually third party sellers do a mix so some people get brand new, others not so much). Also beware third party sellers and Amazon itself often sell OEM drives without warranty. I always check the serials online before opening the anti-static bag to make sure it’s in warranty.
Also: shucks.top
You need to wait and watch for the good deals but they come around multiple times a year.
Also, understand there are certain storage ranges to get these prices. Generally 8-18TB drives are best deals per TB. You pay a premium for 20-22 top size drives as well as for smaller drives like 2-4TB. 14TB seems to be the current sweet spot most of the time.
Lastly. Understand SMR drives are alright for backups but not ideal for streaming high bitrate content from or using to seed files. CMR is better.