Hi OC_WPC
Yep I have been an Open Office and Thunderbird user for a number of years at home.
In the past I have seen schools who totally maximised their IT budgets and bought new hardware with what they saved on licences by going over to Linux and Open Office.
Yep running Linux Servers and Workstations has their own quirks. I am running a few as Veeam Proxies at the moment.
MS is forcing most of us into a learning curve for Command Line Power Shell to do anything serious in Office 365 Online anyway so there is even less reason not to bite the bullet and take on the learning curve of Linux and Open Office.
Even if you go Open Office under Windows its is worth the saving.
Just don't expect to do anything with Access.
It has a DB App but it is Java based SQL.
Trouble is that the users who like many of us grew up using Word, Excel etc. the learning curve is also steep for the end user.
Still as MS keeps changing the UI on everything regularly even staying with MS is a learning curve :(