The Amherst Model Railroad Show in Springfield MA. Excellent show. THE one to go to in New England. I'll be there.
There is a difference between "Train Shows" and "Swap Meets" Train Shows have retailers, layouts, maybe some manufacturers and guys selling estates, their unwanted stuff, and so forth. "Swap Meets" may have a layout or two, little or no manufacturer presence, maybe a retailer ot two turning over inventory that's being blown out because it's been in the shop too long. The majority of vendors are guys doing the "from my basement to yours" thing. With these its always "buyer beware" Used equipment generally sells for 30-50 cents on the dollar with only the nicest stuff bringing 50 cents. Great places to pick up odds & ends, or junk freight cars to kit bash or practice weathering & airbrushing. You never know what you'll find, which is what makes them fun. There will be those where you find nothing.
Manufacturers seldom go to regional shows unless they are local, and never to swap meets. It's just too expensive. Travel expenses, salaries for employees, booth/table space all add up, and marketing budgets have their limits. It's getting more and more expensive to go to these. I just finished Trainfest in Milwaukee. A single booth there is roughly a $1,000.00 investment, then folks want deep discounts. Heck of a way to make a living! That's why you are seeing less discounts.