I do strongly believe you need to know what you're looking for and what it's worth.
Thats the rule of thumb around here. Last one I went to, there was hardly any guns at all. I was disappointed. But I did find a pellet pistol for $20. Couldnt argue with that. Great for plinking out the bedroom window. Mostly just crap though, t-shirts, tasers, toys, TONS of airsoft. It was lame.