I don't disagree or anything, but if a user really wants save money and doesn't have demanding computing needs, another option is to purchase used, refurbished, and end-of-lease computers. According to
discount PC, laptops can be had for around $350, and desktops start below $200.
Of course, you'll be foregoing warranty and possibly power consumption, but it's a cheap way of getting an low-end box, even if someone is not technically-inclined.
On a separate note, let me just say that I LOVE Linux (actually, I prefer BSD, but that's just a personal preference). Ubuntu, for example, is very easy to install, or better yet, Knoppix and similar live CDs doesn't even require installs (but at the cost of boot-up speed). The only downside is that, if you use it long enough, you're going to need some technical expertise sooner or later (or know someone who does). Still, it's a good way to keep the cost down.