A group of Microsoft Products and technologies used for sharing and managing content, knowledge, and applications.
Hi George
Many thanks for your quick and thoughtful reply. It wasn't what I was looking for :-) but that's on me for not clarifying.
What you've just explained is the "free" storage we get with our plans and licenses. In your scenario, the test tenant, that's 1 TB + 22 x 10 GB = 1244 GB.
The obvious next step is, what happens when we need more than that, say 20TB? This is somehow answered in the page you mentioned, Add more SharePoint storage to your subscription. But even there there's no cost written.
For other MS services, for example everything in Azure, the cost is clearly documented. See here how nicely it's explained for Azure Service Bus! Using this information I can calculate the cost for my scenario or simulate a number of scenarios before I even open the Azure Portal.
And here we come to my actual question, or maybe call it request: the extra cost for Sharepoint sites is very poorly, or should I say almost not at all, documented. I need this info to support my work (POCs, yearly reviews, projections etc etc) which of course always includes a cost assessment. Right now I don't have any supporting documentation other than blog posts. Per the instructions in the "Add more SharePoint storage to your subscription" page, I would have to try it out to see the cost, or maybe call our account manager, which obviously slows things down massively.
So my request is: we Sharepoint users, especially corporate ones, need a piece of documentation, comparable to the ones for Azure or other services, that explains the cost of extra storage upfront and clearly.