How to calculate the price of a Windows Server and 1C license?

Question

Windows Server

In our organization, the issue of buying good server equipment for creating a domain controller (DC) has ripened. The server is already included in the purchase, now it remains to deal with the OS.
In fact, I can raise DC on some Debian, in our case this will be more than enough.
But then I remembered that we are still working with 1C - now it is on a pirated win server 2008, they connect to it via remote desktop. Only 5 people work with 1C.
Now the actual question:
1) If I do everything on Windows, will I need user licenses?
2) If I do it on Linux, can I put Win Server on the virtual machine, and already there 1C? Do I need user licenses for Remote Desktop?
3) Is it possible to work with 1C on Linux natively? What licenses are needed in this case? 1C for Windows, we seem to have a face.