Slightly off topic: is anyone using B2 (which seems cheaper if you have more than one computer for a certain amount of data) for personal data backups with strong client side encryption across multiple platforms (Linux, Mac, Windows)? If so, how do you handle it?
I sync all my device files to a local Freenas server which runs duplicacy in a jail and sync's it every night to backblaze B2. I looked at duplicity, restic, attic, borg and in the end settled for duplicacy. Pay attention to the duplicacy license, for somebody it could be a problem.
I do this, though not from Windows, just Mac and Linux. I use restic, which has B2 support smd handles all the encryption. it also does diffing for backups. There's a Windows build, so I assume it would work for you there as well.
Similar to the other two sibling comments, been using restic to sync to B2 over the past 6-7 months. Stored amount has been 450-475 GB, and total costs tend to be about $2.50-$2.75 per month.