I went on one two weeks ago and had a blast. I didn't go with any of my friends- wanted to meet some new people.
I brought my hexie handwork(so did my neighbor on the bus) for the quiet times.
I also made a list of anything in particular I was looking for, and brought a couple fabrics to match with me. They furnished plenty of water but I did bring carrots to snack on.
Money...I spent a couple hundred but I managed to get everything on my list, so I was pleased. I have a very large LQS at home, so didn't know what to expect. It was fun to see different fabric, samples, and meet the people. Set a limit for yourself and have a blast!!! (oh, mine was one long day trip)