I was in Billings a month ago and priced Michelins there because of the no sales tax issue, but was quoted similar prices to what you got.
The local dealer (Plains Tire) in Gillette, Wyo wants $164 mounted and balanced if memory serves me right. I'll probably buy mine at Sam's Club in Casper. I think you need to do some more shopping. I believe Sears was justing advertising a sale on Michelins, but we do not have their automotive dept. here. Not sure when it ends (or ended).
Kim