It’s not hardware cost. This is a TCO analysis, total cost of ownership.
Not easy to do.
I can see Macs costing less re support costs. Just consider what a mess it is keeping Windows machines patched. This is a regular ongoing source of OS and application failures. If you have a patch schedule you know that your heaviest trouble rate is the week after patch day.
Conversely, Windows machines tend to run an application menagerie way beyond what the Mac users do- normally vanilla office apps, for most scenarios. With a very few exceptions.
This application problem is why a large company will have considerable numbers of Win 7, XP, even 95 and DOS machines around - porting something weird is often difficult or expensive, and that sort of stuff is far more common on Windows.
“an application menagerie way beyond what the Mac users do”
My how condescending of you!
This Mac user has a WIDE variety of applications on his Mac, including a copy of Windows 7 he runs under VMWare Fusion. In fact, I have two flavors of Windows and a Unix distro on my Mac right now.
How many operating systems can your Windows box run...simultaneously?