Well, Mac OS 10.0 in my opinion should have been a no charge beta. 10.1 and 10.2 were not exactly awe inspiring, 10.3 was starting to get good, and 10.4 was excellent. So it took a few years for Apple to get in right. There were some features in 10.5 that were better than 10.4 but overall I still like 10.4 better and I thought I had trashed my computer when I installed 10.5. I had one of those BSODs for several minutes. Who knows about 10.6-it has not come out yet. And all of these operating systems that Apple charged for were Mac OS X operating systems. Nobody seems to complain about being charged for version updates.
Now what would have happened if Microsoft had charged for Windows XP Service Pack 1, and Windows XP Service Pack 2? Instead, Microsoft lets people download the service packs for free. I had an older version of Windows XP and at that time just a slow dial-up internet connection. I got in touch with Microsoft and they sent me, FOR FREE, a CD with Service Pack 2. How is that for customer service? Say what you like about Microsoft but they have always treated me well.
In the same time period that Microsoft will have had three desktop operating systems (Windows XP, Vista and soon Windows 7) Apple will have had 7 versions of Mac OS X (Including the upcoming 10.6) and Apple will have charged for every one. Yes they had free updates like 10.5.7 but they will have charged for 7 versions of what THEY called the same operating system-Mac OS X.
But the really big difference is what it costs for the computer hardware to run those operating systems. When Windows 7 comes out I could probably walk into a store and buy a Windows computer that is adequately powerful for something like $900 dollars or even less if I could find a computer on sale. I saw an ad recently for a Dell computer with a very nice graphics card, powerful processor, large hard drive, AND a large monitor for about $1000 dollars. Sure you can buy an iMac all-in-one for around $1000 dollars but to really match the Dell with its large separate monitor you would have to buy an Apple MacPro for around $2700 dollars-no monitor. By the time you have bought a nice monitor for the MacPro you will have paid three or even four times as much money for a computer that basically can do what the Dell can do. And you can keep updating that Dell, even getting a new processor, new power supply, etc. I think the Dell I mentioned even had Blu-Ray. Plus when Microsoft comes out with Service Packs for Windows 7 you will probably be able to download those Service Packs for free. Not be charged for what is basically an operating system upgrade.
Maybe my math is faulty but it seems like a big difference in cash to me.