Yeah, the regional divisions are tricky (especially for someone like myself, who's only lived in large coastal cities). But from what I understand, Lawrence is a decent-sized college town with two universities in it, so not exactly rural. Then again, I know people who would consider everything in Kansas to be rural by definition. (I think such people are snobs, but they certainly exist.)

John was a mechanic, which is generally viewed as working-class, but he co-owned the garage where he worked, and small business owners are generally viewed as middle-class, I think. John and Mary's house looked large and quite nice, even if it did probably cost less than my 1-bedroom condo.

If the Winchesters weren't middle-class, I'd say they were at least headed toward it at a good pace.