I've only been to three Yorks, and I think at each of them I had purchased an item that I thought was one thing but was really another. The latest was a Marx Wells Fargo set that had a wedge tender instead of the wood tender, complete with repro stickers. I'd be upset about it if it didn't look so good like that. Another time I bought a set of green 2400 cars and didn't know that they didn't originally come with silhouette inserts. I also didn't notice that one of the roofs was a different color than the other two until I had them on my better lit layout.
I consider these types of misadventures a learning experience. I'm not out a bunch of cash, and the items still run fine on the layout, so it's all good.
J White