This offer from Polarbackup is jaw-droppingly good. It’s cheaper than purchasing a 5TB hard drive, and you gain access to full cloud backup capabilities to boot.
At $79.99/£66.75 for a lifetime 5TB subscription, Polarbackup is cheaper than buying a hard disk drive of equivalent capacity. Lower capacities are available, but the 5TB version remains the cheapest at less than $16 per TB.
Your data is never deleted (as the subscription never expires), you can back up an unlimited number of external devices – from USB drives to CCTV systems – and Polarbackup even supports file versioning.
Just bear in mind that this is a cold storage service, which means you won’t be able to retrieve files instantaneously. You may have to wait up to 12 hours (but likely less) to access your files, which could pose issues for some.