Check this out...
Vista - a $6 Billion Dollars Operating System - The best billions Bill Gates has ever spent - Softpedia
I don't really know what the markup of it is but let's assume that they make $100 off each license on average (which is a conservative estimate wouldn't you say?).
If my math is correct, that's $18 billion dollars as of the last public claim of 180 million copies sold.
Microsoft: 180 million Vista licenses now sold
If my math is correct again...that's TRIPLE the initial costs!
Of course they likely spent a little more after-market like for Jerry Seinfeld and stuff like that but I don't think it’s anywhere near $12 billion dollars.