There's no way that 26-year-olds can afford a 1500sf house in those areas because the only jobs available are at Walmart. The places where 26-year-olds can get good-paying jobs are also places where the real estate is much more expensive.
>Where in the country can you not make $15/hr by age 26?
Any town where the only jobs are at Walmart and the feed-and-seed store. Walmart doesn't pay those kinds of wages in rural locations (or probably anywhere else, unless you're a manager).