Looks good
At this price it is competitive with storing the data yourself on a couple of hard drives.
There doesn't seem to be much information on the redundancy/reliability though.
Backblaze, the disk reliability statistics-publishing cloud data-centre operator, says it has the world’s lowest-cost cloud storage, beating Amazon and others, with its B2 Cloud Storage offering. The company is known for its personal and business software that enables Windows and Mac users to back up their files to a Backblaze …
Google Backblaze and you'll find all you want to know. This company is the most open about the technology it uses than any other cloud outfit that I know of. Here, for instance, is details of the latest iteration of the Backblaze Storge Pod. https://www.backblaze.com/blog/storage-pod-4-5-tweaking-a-proven-design/
The company leverages commodity (and desktop-grade) hardware to the max, combatting the intrinsic lessened reliability with very large degrees of redundancy. FWLIW, IMO, that's the smart way to go.
Reliability? Like all of the consumer backup services I've tried, they have their weaknesses too.
I had nearly 4TB of data on Blackblaze (took nearly three months to upload it all) and it worked great keeping everything in sync for about a year. Then one day it stopped syncing new files. Spent a bunch of time going back and forth with support and they tried really, really hard to fix it, but in the end the answer was, blow away everything and upload it all again. With no off-line upload option available at the time (not sure if you can send them disks today), I gave up and just started doing multi-copy local off-site backups, swapping physical disks.
So I guess the answer to reliability is, do you have a fallback if something goes wrong? I think Backblaze is better than most of the other services but they're not perfect, and when ALL your data is sitting there and something goes wrong, you'd better have a "Plan B".