Most companies never do a TCO analysis. That's a fact.
Their IT departments won't do it . . . for the simple reason of that equation of 1 IT guy for 18,000 Macs vs. 1 IT guy for 500 PCs.
The director of IT LIKES having a lot of people working underneath him.
It means job security. . . and a big paycheck when he's the boss of that many people.
He's not going to be the one to tell the CEO that his job and a lot of the guys and gals he has working for him, and the budget for his department, are completely superfluous and a waste of company resources.
No, he won't be telling the CEO or CFO that inconvenient truth. He will bury it as far down and is deep as he can. . . just as you are trying to do.
Frankly, every single time that I've been able to switch a Windows user over to using Macs, I've stopped making money off of them. It's inevitable.
Good thing most of them simply don't believe their business can use Macs, no matter what I do to show them and prove it to them. They listen to their peers who tell them the only way to go is Windows. I will go on billing them and making money from them, cleaning up the inevitable messes. A few do listen. . . and also inevitably thank me for switching them over. Some have even switch for their home use, but fear keeps them from switching the businesses. Fear and peer pressure are powerful non-motivators.
They all say "I wish my office work was as easy as what I do on my Mac at home."
Eventually they'll switch.
When enough people switch then you can start making money off the crap that is targeted to a Mac. It ain’t special.