Thanks for reading the article Bruce Dunlevy.
Just to add. The people on the RepowerAndRegear groups.io list frequently discuss the various ebay motors. They are mostly into HO standard gauge so much of the motors are larger than we would use in HOn3. That said, there is a lot of good information on that list that applies to HOn3.
I've found that the ebay motors are hit and miss and I've ended up buying quite a few over the years before I found some that I really liked. Usually I'd just order a couple at first to try them. Once I find a good one then I'll stock up with a larger order if they were still available. The coreless motors are usually about $11US. The Mabuchi motors are $2-3 and run exceptionally well. Certainly as good as a coreless and the torque is unreal. The big problem with sourcing motors this way is the long shipping time from China (1-2 months) and getting a chance to order again before the motors are sold out. The various motors come and go all the time. Also FYI, if you do a bulk order you can often negotiate a better price. Even with all the hassle of hunting, I've scored some really fantastic coreless motors for cheap prices over the years.
I used to buy from Eldon Shirey (motorman) before he passed away. His coreless motors were often $40-50 and cans for about $20. He always had a great selection and good information. His passing has left a large void in the hobby. NWSL carries a nice line of can motors too. I'm pretty sure they are the same $2-3 motors on ebay except they've done all the testing and sampling of motors for you. I do have a bunch of motors off ebay that turned out to be duds and I'd think NWSL does too. If you want sure thing without the hunting, NWSL files the void nicely.
I'm working on an upcoming "Brass Bashing" article that uses the Maxon coreless that is second from the right in the photo. It's exactly the same size as the Faulhaber 1319 which was IMO the king of all HOn3 motors. The Maxon seems to run as good as the Faulhaber. Unfortunately, I haven't been able to source that motor again on ebay. I did buy a half dozen though. I wish I bought more.