Shop around. After you have looked at most of the tables at the show, you will have a better idea about who really knows their stuff and who is just trying to make a quick sale. If you see something that is a lot less expensive than what others are selling similar items for...be cautious.
Most of all...look around and meet people...have fun
If there is anything the nonconformist hates worse than a conformist, it's another nonconformist who doesn't conform to the prevailing standard of nonconformity.