I buy and sell Lionel trains. Mostly Post-War '50s stuff. Its a huge market on ebay. Lots of bidding wars on the unique items. Best time to buy is now, summer months, then sell in winter months. Gotta know what your looking at though. Quite a few repaints and questionable items as well.
It was common , in the Chicago area anyway, for bike shops to sell trains and hobby stuff in the winter months. I would imagine anywhere in the northern climes that would have been true. The interest in hobbies has gone the way of the dodo with the total addiction of kids to video games though. Most guys that buy trains are geezers looking for the nostalga of toy trains. Myself included!