I'm building myself a new box and I can probably get double the performance of this Mac toaster for half the price.
Building a machine is the way to go if you have any computer know-how whatsoever. I put the money where I want it, cheap out other places, and design it to be upgradable for the next five or so years. Plus if something breaks, I can fix it - can you get into this Mac and upgrade the memory if you want? Add a new generic hard drive in six months?
I just built my first computer 2 weeks ago, and in the future, I will no longer be buying already-assembled computers. It's really not that hard to do, plus you can watch for the Newegg.com daily specials and pick up some good deals.
Windows XP will eat up most of that "1/2 the price" of this Mac mini. But then again, I'm sure you are not including your cracked version of XP in the cost of your machine. Nor any of the other comparable software that comes with the mini as well.