My mom (and my dad before he died) have lived many decades in Houston, Texas. Homes in Houston are very cheap because land is cheap because zoning is shit (IMO). That being said, energy costs only ever go up.

I've always thought that you could increase the cost of building in Houston by 50% making thick, clay brick walls to save huge amounts long-term. Basically build standardized versions of adobe houses that indigenous people have been building in that climate for thousands of years. You'd get your money back in probably a decade or sooner with reduced energy costs. Not to mention the air inside a naturally insulated house is much nicer than A/C air.