I don't know how much it costs (a boxed version of Vista Ultimate might cost around 7 units), but when I bought a computer with a pre-installed OS, I wasn't charged extra for it (at least, configurations with XP and Vista cost the same). In general, it's better to build a computer yourself; I realized that a long time ago. ^_^

Added 4 minutes later

I'm not arguing with that – it's true. But do you know how much Vista costs? Around 100 USD and more, depending on the installed version.

Unfortunately, I do.

So why should someone pay for something they don't need? That's the most interesting part. What if I already have purchased software, and with that money, I could buy better hardware? And it's not just about Vista; it's about any software. Vista is just the most striking and well-known example of consumer rights violations.

In most cases, the average person, whose computer experience is limited to Word/1C/Paint/Explorer, simply doesn't think about it because they don't understand the subject.