The friends I was talking to in Phoenix were not looking for a run-down low rent house. There are probably quite a few of those for rent in central Phoenix. So I guess they were not counting anything that rents for less than $900 per month.
I am not trying to be a smart alec...I was in the area in May, and my buddy's new subdivision had about 30% of it empty with rental signs on it. He has a coworker that just rented a year old 5 bedroom house with a pool for $800/mo in the West Valley.
If you go to realtor.com, and search Phoenix, add the surrounding communities, even selecting rents over $500 and sq foot over 1000 you get 2389+ listings
a better indicator is craigslist, which are person to person ads that probably arent even included on the realtor.com listings
http://phoenix.craigslist.org/apa/