Normal S3 would be ~$1.1k/yr, or around half of that for the infrequent access tier, both of which are way too expensive.
Backblaze B2's calculator is a little more sophisticated, and putting in the numbers for an absolutely pathological usecase where you start with 4TB, download, delete and upload that same amount every month puts you at $720/year. A much less pathological use case (I think) that assumes you upload, delete and download 1TB/month puts out around $360/year.
Hetzner storage boxes offer 10TB for ~$48/month, which is $576 a year -- free ingress/egress, no hidden fees for operations or whatever else, but you do have to set up a node with minio (or use FTP, etc).
Amortized over the happy time (time where you don't need to rely on your backups) this does make sense, but I wonder what the percentages look like on that kind of metric. To be fair I haven't had to restore from backup for years so this probably makes a lot of sense. I guess there's no need to test your backups/restore either if you're using a tool like borg/restic/etc and have tested it with local hardware.
Also, what happens if you have to retrieve data twice from Glacier? You've got access to it for 24 hours so I assume you're planning on just keeping the data on some non-glacier storage medium for a while after the initial post-disaster pull?
Part of my calculus is that I have quite strong confidence in AWS in terms of business continuity and reliability/availability. If I dump my files on AWS, I have high confidence in the files (and AWS) being around in 10 years and retrievable for roughly the same price (or at least no more).
Hetzner would have much lower durability. I'm a bit suss on Backblaze, though I do trust them to be more durable than my self-managed disks (and uncorrelated to my failures). I don't know much about Wasabi; but it's not a good sign for me that their landing page touts their latest funding round at the top: seems young and you never know if the price is subsidized with VC money (and won't be in n years) or similar.
> Also, what happens if you have to retrieve data twice from Glacier?
The killer is the egress. I'd just buy a new set of disks and download it straight there.