While Cool and Archive tiers are less expensive per GB, they are designed for different use cases than hot storage. Please make sure they work for your particular needs before implementing. You can read more about them here: https://docs.microsoft.com/en-us/azure/storage/blobs/storage-blob-storage-tiers Calculator here: https://azure.microsoft.com/en-us/pricing/calculator/

If you change the backup plan, any data already uploaded to Azure Hot will remain in that tier and new data will go directly to the newly selected tier.

I'll add that there are other cloud storage vendors that may have prices more in line with your needs. As an alternative, check out Backblaze B2 and Wasabi as possible options. You can see the full list of supported cloud storage vendors on our web site here: https://www.msp360.com/solutions/cloud-storage.aspx

David, the calculator was wonderful, thanks! It reminded me of the Redundancy tiers Msft had and that makes a huge difference in cost, more so than storage temps. This way I could leave my backups as hot for quick restores, and hope Msft takes more care of their local data centers than they do in releasing monthly patches that wipe data.