Believe it or not though gaited horses up here generally still sell in the $1500 and up range if they are well broke. Up here even in IL we are wealthy with Tennessee Walkers so they often will sell for $700 or less well broke.
The recommendation for a mountain horse is solid. I have a 20 year old mare that gaits like a dream. No trot, no pace, just gait. Smooth canter too. Both of my youngsters (One is 6 months and the other is 2 already show gait and they haven't even been worked with for it). I would agree that you should see what is in the area, with winter moving in you may find one on Craigs List. Yes they do show up there on occasion. Lot of people in the Great Lakes Area still losing their jobs due to the economy that the media people tell is is getting better.