I'm not sure this is really true anymore and it ignores the reality on the ground of "cheap areas". Often times cheap areas are underserved in a way that once you require or depend on a service that is baked into other higher cost of living areas your life becomes much more expensive than if you'd simply lived in a high cost of living area. There are many examples of this but hospitals in rural areas are one of my favorite examples. There used to be many of these but many people didn't realize they were all (or mostly) subsidized capital ventures. Many of them are closing now that the subsidy has ended. So, is that county land cheap? Yes, but when you have an incident where time matters your likelihood of being cooked goes up precipitously.