Marlespo might be a good source of info for you, if she can ever get time to post! She's busy with a new baby right now. They just moved over here from the Midwest, I believe.
You know you'd lose the council tax payment, but also you'd lose Child Benefit & Tax Credits income. I'd imagine things like car payments, car insurance, petrol, miles driven, etc - things like that would increase. Minus public transport costs. Health insurance is a biggie - if employer-provided, then that's better but often extra premium is taken from salary to cover the family whereas health insurance for the employee-only could be provided completely by the employer, but not always.
I haven't lived in the Midwest since 1997, so no idea on current costs, unfortunately! The one thing that strikes me since I've moved over here (from 2004) is that the price of food has gone up phenomenally in the US since I left. Like I'm shocked at how much food costs there now - probably due to the price of oil, transport costs, etc?
You might want to look into tax favourable areas as well - like what taxes do you pay living where. For instance, when I lived in Florida (not Midwest), it was just federal tax & some sales tax (but not sales tax for some things). However, when I lived in Kansas City, Kansas metro area & worked on Kansas City, MO side - I paid federal tax, Kansas state tax, a bit of Missouri state tax, city tax, and sales tax! It was crazy!

(though probably nothing like taxes here, but at least we have NHS etc here)