If you are willing to travel 2 to 3 hours south, there is Brasseur Model Trains in Saginaw, MI, a forum sponsor, that carry a lot of 3-rail trains. Their upstairs veranda / loft usually had some consignment models at great prices. Riders Hobby, further south in Flint had a little bit of every scale, not a lot of O-Scale . But my experience was from 8 years ago when I lived in MI.
These are just my opinion,
Naveen Rajan