According to 24/7 Wall St., most of the towns are in the Rust Belt where economic instability has persisted, which has kept home prices low. Factors considered in coming up with the list include cost of moving, rent appreciation, inflation and mortgage costs of 20% down payment on a 30-year fixed mortgage at a rate equal to the national average of 3.5%. 24/7 also looked at unemployment figures and home price changes in the areas.