This is also the case of every company I've seen that decided to migrate away from windows based workstations to Linux ones.
They've spent a fuckload of money on porting their tools, training, hiring linux support guys for end-user related tiers and then still nothing worked like they've planned.
Also Office is pretty much free in the enterprise world you pay pretty much absolutely nothing for it the majority of the costs go into CAL costs mainly for Exchange which you'll use Outlook to access. Even if you do not use Outlook to access exchange you'll still pay for those CAL's just that the pricing will not go through the office license but now through the Exchange one, same thing goes if you are using SharePoint for collaboration etc.
If all of a sudden you stop using office and you don't pay those 93.4$ Band-E prices per installation or w/e you'll notice your exchange License pricing to go up the next day to accommodate for the built-in CAL license in office which you do not get with 3rd party software.
This is not how the people working in the Munich municipality tell the story. [1] Although the new city major has made statements of wanting to go back to Microsoft, [2] apparently the open source system is live and well. [3]
So it seems that the whole story that "Germany switched from Windows to Linux, only to regret it years later" is a myth.
[1]http://www.techrepublic.com/article/no-munich-isnt-about-to-...
[2]http://www.techrepublic.com/blog/european-technology/mayor-o...
[3]http://www.ocsmag.com/2015/08/24/no-munich-is-not-considerin...