As you saw in this book, Azure Stack is the optimal basis for running Azure workloads on your own or your service providers' private cloud solution, mostly connected to the Azure public. As of today, Microsoft is the only cloud vendor that provides a hybrid cloud solution with 1:1, which the same technology that is running on Azure today.
In regard to TCO and RoI, there is a great option to order not just Azure Stack as a software and be responsible for setting it up by yourself and making it run properly. This could mean weeks and months for the deployment. Azure Stack comes with the hardware solution as an integrated solution. You would only have to set it up by connecting it to the internet, power it on, and provide cooling and rack space. So, it may take only a few days to have Azure Stack up and running and in place.
The more interesting point, then, is to design your services in a way you would really need them. This solution design is not a technical deep dive; it is more a...