It's an odd way to present the data but I got over it.
It's important to remember that the data will apply to you only if you behave like the average person everywhere. Their data says it's 5% cheaper in Raleigh than DFW. After migrating from DFW to nominally Raleigh, my experience does not agree. Everything I actually buy is slightly more expensive here, including real estate that fits my needs.
DFW probably looks more expensive on paper because the median and mean spending and prices are all higher, but many of those prices are for things that don't exist here, or for things I wouldn't buy anyway, or things that are just out of my budget. Sure the average restaurant meal is probably 20% more expensive in DFW, but I don't go to expensive restaurants; I only care about what I can get for my family for about 25 to 30 dollars before tip that I can afford, and by that measure, and analogous measures across the board, the expensive place was cheaper. What the average family pays for transportation in Plano (the most affluent city in America) is probably quite high what with the beemers and brand new Texas Edition megatrucks everyone drives. But slightly-used minivans I actually care about are still cheaper there.
What figures like this tell you is what it will cost if you make the average and then spend yourself into the average. But you don't have to spend yourself into the average. With real estate in certain areas, you may be forced to spend more. Maybe, but not in my case was that true at all.
My professors in rural Ohio used to encourage me to move back because "cost of living" is so low, but really the standard of living is low, so you can be pretty well-off there, by comparison to your neighbors, on the 75k per year I made at the time. But I would actually get less for my 75k per year there than I would have in DFW. That's not lower cost of living unless keeping up with the Jones is a prime directive for you. Myself, I didn't mind living among the affluent and availing myself of the good prices, clean stores and healthy markets that cater to them while making a decent salary. Then again, if whitetail hunting, being close to family, and being able to see the stars at night matter, then that changes everything too.