As for a fair price, I think Cloudflare and BackBlaze provide S3 API compatible services with better pricing. Cloudflare doesn't charge for egress at all. This lends substance to their claim that AWS is overcharging for egress.
My opinion is that Backblaze has done an awesome job of driving their storage costs down, scaling that up, and then reflecting that thriftiness in their pricing. Their technical communication (e.g. hard drive reliability reports, software engineering blogs) makes me believe in their competence. So when Backblaze sets a price, I expect that's pretty close to the minimum sustainable price, because they've spent a lot of effort on that.
B2 currently charges $5/TB/mo with lots of options for bandwidth that's too cheap to meter. This strikes me as pretty fair overall.
But the bandwidth is a huge issue.
[1]: https://help.backblaze.com/hc/en-us/articles/218485257-B2-Re...
And if durability is your main concern you'd be on a cheaper S3 plan anyway.
> I'd still argue the 4.6x cost difference isn't worth that for a lot of uses, though.
Sure. S3 and B2 have different strengths, and B2 is better for many uses. But looking at the full stack and the performance at each layer suggests to me that S3 charges a reasonable/fair price for storage. And that's what the question was about.
I haven't had a problem with the storage prices, just egress fees can add up
(I don't work for aws or a cloud provider, just curious)