Seca:
I've been going to BeadFest and Intergem shows at the VFCC for years, and this is a bit of a brain dump:
What to wear: Comfortable shoes are a must, and a backpack is a good idea too, even if you aren't planning on buying anything heavy. You'll be surprised at how quickly a purse or handbag will fill up and get extremely heavy.
Since this is the summer edition, wear light clothes and leave the rings and jewelry at home. It's a temptation to wear your creations, to show off to other beaders, but you'll soon find that anything heavy around your neck and on your hands will be a burden.
Parking: The parking at the Valley Forge CC is nightmarish, especially in the summer. There is a lot of it, and that's the problem. If you part far away, you'll be up a long hill, and trudging back to your car in the heat and humidity (and quite possibly the rain, looking at this weekend's forecast) is extremely unpleasant, so get there early to get decent parking.
Meals are tricky - the food at this BeadFest venue is notoriously awful. For the past few years, I've brought my own, and I recommend you do the same if you can. There's a decent sized area with tables set aside for dining, and they don't object to bring-your-own. Although you're going to be near the King of Prussia Mall, you won't want to leave and lose your parking spot.
Budget: Well, that's an interesting topic. How disciplined are you? Be prepared to exceed it - it's inevitable. What's helpful is to not buy the first things you see, if if they are what you want. Chances are, you'll find better prices as you get deeper into the show - vendors pay a premium for the booths up close, and charge accordingly. Also, by walking the show first, you get an idea of what's out there, what you want, what strikes your fancy, and what blows you away.
Bargaining: Many dealers will do better if you ask. Do you have a resale or wholesale license? Vendors will definitely give better prices for wholesale - even if you aren't buying in quantity
Some things are actually more expensive at shows - I don't buy delicas or swarovski unless I absolutely have to have it NOW - you'll always do better at FMG if you've got a big order.
Know your prices and check all vendors before buying - particularly for hill tribe/bali silver. Vendors often price by the gram, and prices can vary from $1.25 per gram down to $.65 per gram.
Miscellaneous: Take a small notebook or pad with you to make notes about potential purchases - there's nothing worse than trying to remember where you saw a particular bead. This is a big show, and it's on two floors. You can go crazy looking for a booth, only to find that it's on another floor.
Verizon cell phone service doesn't work in this building, but ATT gets 4 bars. Weird, but true.
Hope this helps, and have a great time! I'll be there on Saturday, I can't wait.
Lita