Can you use a gift card for the F&W Festival booths?

[aussiedaisy]

I had read in someones recent trip report that when they went to the Food and Wine Festival they bought a special gift card with a wrist attachment to use at the booths. Just wondering if anyone can confirm where you get this gift card from and if all the booths at the F&W festival accept it? I think it's a GREAT idea as last time we went, we used cash and ended up with heaps of change which I still have (I'm Australian so can't really use it). Hope someone can give me an idea of where I can get one. Also, how much do you think we should put on the card if we get one. We want to sample most of the booths as well as have a margerita ir two I was thinking $100 for two of us? What do you think? Thanks!