This might be true in the expensive metro areas but its doubtful that it applies across the country.
In fact I just checked craigslist for Little Rock AR and found lots of two bedroom listings at $500/month, some of them single family homes.
3149 W Gracelawn Ave Flint, MI 48504
•2 beds
•1 bath
•900 sqft
•6098 sqft lot size
•Single-Family Home
For Sale By Owner $6,500
30 year mortgage would be somewhere around $50.00/month
There are several listings under $10K.