Yes charging. And every .x release they charge for I believe. Not much but it’s typically $30 I think.
Ah, for-q. You really need to get out of the basement more often.
Apple hasn't charged for even the MAJOR version releases of OS-X or their applications, in many years. They come free with the purchase of the hardware, and are updated for free for the life of the product.
What you're probably thinking of is that if you buy certain large applications (e.g. the iLife suite apps like iMovie) without a hardware purchase there's a nominal charge, $15-20.
But the operating system versions and upgrades are all free. Charge for "every .x release"? You're dangerously high. Thorazine, perhaps, is indicated. :-)