I didn't read all 5 pages of this thread. I'm just a local weekend camper. The casinos around here charge about 30 bucks a night. They have nice level cement pads. But, there quite plain. Not camping in nature, just a glorified parking lot.
The local county, out of the way, parks I frequent run 17-22 dollars a night. They don't have full hook up's. At 17 a night you get electricity and nothing else. At 22 a night you get electricity and water. The sites are gravel, sometimes unleveled, (though not always) often shaded, and they have more of a camping type feel.
MN state park prices are about the same prices as local county campgrounds. They are much, much, nicer but, you better have a reservation far in advance.