UPDATE: Well, egress is cheaper. B2 is $0.005/GB storage with $0.02/GB egress. But one thing to consider is that B2 storage is located within one single datacenter.
(Disclaimer: I am not affiliated, but am in the process of deciding to use B2.)
You will be better off using any standard OpenStack provider. That way you won't have a lock in, and great performance (in my testing). E.g. OpenStack Swift on OVH.
Sure it's a tiny bit more expensive. But you get a mature cross-provider API and better performance.
Even for huge chunks of cold data, I wouldn't want to use B2.
That it works so well for me might be connected to the fact that their own products are backup solutions. In any case, I am now paying a significantly less monthly fee for B2 than on Amazon S3 before and the setup had a much lower complexity.
How stable is Wasabi?
It looks really promising, and pricing is very reasonable. Thank you for pointing it out.
In the process of moving from one provider to another and it's pretty tedious getting it all in sync while I manually move from one to the other while still backing up to the previous provider until the move is complete.
It's going to be a bit of a process over the next few weeks :(