

Honestly I’d recommend buying refurbished drives and using them in a RAID array so that you can easily replace one for cheap(ish) if it goes bad.
before anyone says “RAID is not a backup” yeah I know but you can’t deny its capability to function as such. 3-2-1 always applies.
Set up an alert for when the drive you want goes on sale/in stock
You can buy twice as many drives, though.