Not model related, but the model train show in Monroe, WA over last weekend was well worth the trip. I found a 1944-dated D&H lantern that was in incredible shape, where someone had punched a hole in the bottom for an electric light. I wanted to do that with a lantern but wouldn’t drill a hole myself, so I got this one really cheap (just over $40 for the lantern and a red globe from another vendor who had mostly lantern stuff). I only need to find a flame-shaped bulb either as battery powered or wired. Heck, I could easily get a burner and use it normally if I wanted to.
I also found a neat EMD unit truck plate set for next to nothing, some good books (including a WW2 Jeep book for $15 that normally retails for about 50 when you can find it), a book on railfanning Stevens and Stampeded Passes (ironic as the Stevens pass line was right across the highway from the venue) DVDs (one vendor had them for $2 each) and some detail items. I haven’t seen that much good stuff at a show in years, it was a good run. Could have bought a lot more stuff if I didn't fear the wrath of my wife! 
For example, a guy had what was a pretty decent price on a complete GN semaphore blade, but it was too much for my wallet and I have no room to hang it anyway.
I also hit all the major hobby shops in Seattle on the way home and found some magazines and random items.
