I've heard a lot of people refer to it as the '(fill in your name) Syndrome': you see something interesting at the show, think "I need to get that/some of those later" or "That's really tempting, I'm gonna think about it", and when you come back it's gone. Or somebody bought ALL of them.
I did that today. Twice. Dammit, I may just start buying it when it looks interesting.
Yeah, I wish.