Why is Phoenix Arizona so cheap for housing?

cheap? it used to be. I moved here to go to MMI back in 1994. One bedroom furnished apartment with utilities included was 400 dollars and change. Now it would be over 1000. To many people moved here. Traffic sucks now. Its much hotter now as well. 

Phoenix is not a cheap place to live.  AZ has a state income tax, and while house prices might be down right now, the overall cost of living is higher than in some other areas of the country. 

It's really not. It's getting more expensive here now. Is it cheaper than San Francisco and New York? Of course, but there are much cheaper places like Albuquerque and Columbus Ohio. Rent in particular is going up a lot here. You need to also stay away from apartments that are too cheap because you will be living around a lot of undesirable people.

Because of all the kidnapping and prostitution. Basically if you live anywhere south of Union Hills you're forced into slavery, the pimps and the illegals are brutal.

The weather is not desirable by many, but also because there is so much available land.  It's surrounded by desert and can continue to sprawl.  As new areas are developed, that keeps prices of all homes down.  The biggest concern with this expansion is the infrastructure, including water, to support it.

Phoenix is very hot and undesirable climate, very spread out so a lot of room for housing development.

Because it has aliens in it