Should you buy a house over renting? If you can afford to, YES.
If you are in the fortunate position to acquire a house without having to take out a mortgage, you are in a much better position then renting for a number of reasons. If the economy collapses or you lose your job, and you own a home then you don't have to worry about coming up with a rent check every month.
At this point, it is unlikely that the real estate market will come back inside of a decade for a number or reasons. I personally think we have yet to hit the bottom, but if you can find the right place I'd say go for it. Bear in mind that people are desperate right now to sell, so that puts a lot of power on your side of the table.
I don't know your personal situation concerning work, family, or even the general area of Phoenix. If I were in your shoes, I'd try to get the hell away from the metro areas if at all possible. Maybe on the outskirts of town??? In a perfect world you would be able to find a place that is out of the way from people and still have a decent commute to work.
If you can get your hands on this book, there's a lot of good info in there. You can always sell it on eBay when you're done with it.
http://www.joelskousen.com/strategic.html