It's a really nice idea that purchases are based on "informed choice," but in my experience, people often buy things for many other, less rational, reasons. Marketers have done a lot of research into this, and there are people who will put a lot of thought and research into a purchase, obsessing over getting exactly the right thing for the intended use, and then there are people who will just buy the first thing that they come across, or buy what their friend has, or buy the one that comes in a pretty color, or whatever. Amusingly, the second group is generally happier with their purchases, though I suspect the first group probably defends their choices more, having invested much more in it.
