I agree with Mike.
Check out the current On3 listings on BrassTrains.com:
https://brasstrains.com/Classic/Trains/Scales/On3-ScaleThere are far more D&RG brass models than any other prototype, prices vary from the $600-900.00 range for MMI "hybrid" models to $1,000.00 to $2,000.00 for quality brass models.
The rarer prototype models (WLCo. shays, C&S 2-8-0) are priced higher.
With the O scale narrow gauge interest being diverted to the On30 market in the past 15 years, I doubt that much will be produced in the way of On3 brass going forward.
The hey-day of C&S model production in HO, S and O scales was back when Harry Brunk published his series of articles in the
Gazette.
I like to think that this site and Roper's Discussion Forum have created a renaissance in interest of C&S modeling. Unfortunately, we will all be competing for the same limited number of brass models, from other's collections, as they loose interest or die. I would only expect C&S brass model prices to further increase.
Jim Courtney
Poulsbo, WA