I love gun shows! I'm sure they're run different in the PRK than in New Mexico. Here there are no requirements (other than age) to purchase firearms. Most vendors will want an ID to prove residency.
Most people are honest. I've never had any experience of anything being misrepresentated.
Picked up a vintage 1969 Browning Hi Power at the last one. There are good deals, but the negotiating can be tough. You should go just for the experience.