Go to www.serverpartdeals.com and import from US. High chance that customs are too busy for your private one shot delivery...
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.
Only if it has good SMART, works, and is from a trusted seller.
I always buy new. But the used prices are typically not cheap enough here to make them worthwhile. If I only can save like ~20 EUR per disk, I rather go new than take a used/refurbished one with higher risk attached. I don't buy below 18TB anymore though, so the market for tiny drives like 6TB may be a different situation.
My recommendation check the TB not the drive price. You probably save a lot when you buy larger capacity disks.