It depends. Cloudflare R2 has unlimited free egress; if you’re using a Cloudflare Worker already and proxying the download, then Backblaze B2 becomes cheaper again because egress is free and unlimited.
One useful trick is if you’re already using a Cloudflare Worker, you can force cache fetches to Backblaze B2 (or any S3 provider). This is allowed by Cloudflare’s ToS as you’re using a Worker.
Here’s my rough pricing notes:
https://gist.github.com/Manouchehri/733e6235457e60de24fdbb15...
One useful trick is if you’re already using a Cloudflare Worker, you can force cache fetches to Backblaze B2 (or any S3 provider). This is allowed by Cloudflare’s ToS as you’re using a Worker.