Interesting. I wonder how much of that is because there is dirt-cheap property right next door in Mexico. I offer Tucson and San Diego as counter examples. Prices there are higher than many places much further inland. Here in the NYC suburbs, there is NOTHING for sale under 150K. And NOTHING under 200-225K in anything like a "good" neighborhood. I expect prices to level off or go down this year, though.
Actually there is no dirt-cheap land for sale in Mexico which is why many of them come here because they can live in housing projects or in illegal subdivisions cheaper. Many of our immigrants have no money, no English language skills, no education past 3rd grade in Mexico. They have no money to buy houses and many can't get jobs that pay minimum wage.
This is an example of some of the neighborhoods they come from in Mexico where they use about $150 worth of discarded wooden pallets to build houses and we're seeing similar houses going up all over the place here.