I don't know whether I agree with everything that City Observatory says, but this one is spot on: http://cityobservatory.org/transportation_housing_affordability/ It isn't possible to judge housing's affordability unless transportation (commuting) costs are considered.

If you live in #Las_Vegas, but work in Los Angeles, either you spend more time getting to and from work than you spend at home, or you'll get a small place somewhere much closer, so you can stay during the week and just go home on weekends. Either way, you should include those costs in your affordability figures, because you may find that you didn't really save money versus living in #Los_Angeles County. (I used a #SoCal example, but you can switch to other areas and see the same situation.)