The model you describe is double the cost if your contract written for only "Primary Calls"... if you have "Secondary Calls" in your contract, server calls to additional suites (as in multiple suites encoded into the same server calls) will cost half the primary call.
However, this is not a smart way to implement... With the advent of Virtual Suites (almost 10 years ago), there is no need to use multiple server calls any longer.... Create a Global Report Suite, send all data there. Then create individual segments for each of your sites (I like to use the server dimension, and pass that on ALL hits - page views and actions: domain1.com or domain2.com, etc).
Next, create virtual report suites using the new segments.
Now you will have a global suite, and suites for each site.. and there is no additional costs incurred.
This also becomes easier to maintain... when you need to add a new prop or evar or event, you won't have to select all your suites and try to modify them as a group, or add the configurations one at a time.. you have one suite to edit and that is it.
More on Virtual Report Suites:
https://experienceleague.adobe.com/docs/analytics/components/virtual-report-suites/vrs-about.html?lang=en
Note: a lot of the "limitations" listed in this doc are referencing the old Reports area..
I have been using Virtual Report Suites almost since they were introduced... I used to have Global + Individual Suites and I would never go back to that model.