To add, Black friday is soon, so maybe it worth to wait for it.
Data Hoarder
We are digital librarians. Among us are represented the various reasons to keep data -- legal requirements, competitive requirements, uncertainty of permanence of cloud services, distaste for transmitting your data externally (e.g. government or corporate espionage), cultural and familial archivists, internet collapse preppers, and people who do it themselves so they're sure it's done right. Everyone has their reasons for curating the data they have decided to keep (either forever or For A Damn Long Time (tm) ). Along the way we have sought out like-minded individuals to exchange strategies, war stories, and cautionary tales of failures.
Servus! I think I can chime in here since I'm the target demographic that you are looking for.
I just recently bought a bunch of HDDs from Mind Factory this year, where only a single disk bought in February was improperly shipped and DOA. The exchange was fine, however if you are in a hurry, the delay to get a replacement will take a few days to a week since they ship from north Germany.
Concerning sourcing, generally I will always check a site such as https://geizhals.de/ or https://www.heise.de/preisvergleich/ and perpetually hit F5 a few times a day to check for price changes because auto notifications, I found, can be delayed before they are sent.
Concerning pricing, one thing to look for is the historical data of a certain disk you are interested in to see if there are any price drops at a certain time of the month. If there is, and you are not in a particular hurry to buy disks, just wait for about the same period of time for it to happen again. The lowest I was able to get 6x Seagate Exos X20 20TB disks back in July was at 299 euros each (14.99 euros per TB) by just waiting because the normal price per disk was 320 euros. This is really helpful when buying a bunch of disks at once because, hey, I like to save 120 euros when I can if all I have to do is wait a week or so for the price to drop again.
Happy hoarding!