I'm guessing you haven't been a sysadmin at any midsize to large corporation...

Apple gets a small sum every year from those of us who bother to upgrade. But every few years they get much more than $140 out of us in the form of the purchase of a much higher-margin computer for which they don't have to split the profits with anybody else.

Also, let's compare apples to apples (ahaha). Apple only retails their OS in an upgrade so we can really only compare upgrade pricing. Apple charges about $20 for an upgrade every year, which averages out to $20/year. Windows 8 upgrades are selling for $40 right now, and the last version of Windows came out about 3 years ago. $40 / 3 = $13.33.

Now I absolutely agree with your assertion that $20 is a fairly small sum. But I'm not sure I agree that $13 is a price gouge by comparison.

(Spoken as a Mac and VMWare Fusion user.)

That works out to ~$28 per year. Just a little more than what an OSX user would pay every year.