I spoke with the IT manager of the school and he's a real fan of open-source. He gave a talk at a open-source convention about it (in german)[0]. In this video he talks about how he convinced the local government to budget this, how it saved cost and much more.
I think this is a great example that this can work and more schools should try this out. From what I heard, the teachers didn't have too many problems and my classmats were quick to adopt without many problems. If I'm honest, I experience more problems with the Microsoft stack in my current school.