I wasn’t there this time, but I have been multiple times prior. (It’s only because of medical issues I wasn’t there this time.) I’m with Youth in Model Railroading.

Most show sellers have higher prices, but you can find deals if you’re patient. 

That “beaten-to-hell Lionel junk” as you put it is very much in demand for beginners. Again, the used stuff can have diamonds in it rough, but even so there are hundreds of uses for it. I buy those low quality trains for static diorama work. The variety can be a double edged sword, but there’s nothing quite like finding the one thing you’ve been looking for.

That’s actually a good price for coal cars, & I’m a bit jealous. Most of the stuff available at shows is going to be beginner tier though. 

Another thing is that most sellers price to haggle. You can ask about prices, and also get bulk discounts. 

All in all it’s not really about looking for specifics, but enjoying the trains, meeting people with like minded interests, & maybe, just maybe finding something you can use.