Fun Factory in Overland Park has 7th mix and it costs a dollar. Cool Crest in Independamce has 8th mix and it costs 75 cents. I'd recomend going to Cool Crest, it's much farther than Fun Factory, but if you have the time and a pretty good sized amount of people that want to go, it's well worth it.
And if anyone is going to Cool Crest, for the love of Gawd, let Siege or I know, because we want, no, NEED to go. It's been too long since we've had good DDR.