Vista is not expensive. You can get the best version they have for less than 150 bucks. Look at what people pay for video games these days. Sure $150 may seem like a lot compared to free operating systems such as those based on Linux, but you need to understand that you're getting something with Windows that Linux can't offer:
Compatibility with the majority of computer software and hardware. If you don't know how to code, you probably shouldn't use Linux. Linux is for people that code or improve their own software, and Linux usually improves only when volunteers code improvements. With Windows, you have thousands of people dedicated on a daily basis to improving Vista.
I'm not saying Linux doesn't have it's place, but it's definitely not ready for distribution as a consumer operating system for the masses.