The cost associated with moving to linux include re-imaging computers. And potentially adapting to software incompatibilities, if any arise. Linux actually accounts for most of that already.
In reality moving from Windows 7 to Windows 8 presents many of the same challenges.
Linux is actually a much more secure platform than Windows. And I don't know of any security risks involved with using OpenOffice.
You can't be in the IT field and not know how to support Linux. This is another common misconception. That somehow you have to retrain IT. Fact is when you hire IT individuals Linux is often already a prerequisite whether you use linux or not.
Also as Kangaroo suggested, you can run OpenOffice on windows.
The reality is that most people use their work stations for word processing, presentations, database, spreadsheets, and internet. All of which function in the exact same way on Linux.
I could put some brands of Linux on your computer, and you wouldn't recognize the difference.
Also the fact that Windows has so many more issues creates a much larger tech issue. A lot of that is again preconceptions about different systems.