Well, I do budget myself, but I usually spend all the money I bring! After paying for hotel, gas, and parking (around $200, usually less), I like to have $500 I can blow on the dealers room, artists alley, and of couse a couple good meals!
Basically, I eat at the food court you can walk to from the BCC skywalk for lunch Friday and Saturday. So that's only like $6-$7 for lunch each day. Then, for dinner we usually do two nice restaurants (Thursday night and Sunday afternoon), and one night of going out for a few drinks (usually Saturday, cause we ditch the rave). So there goes around $150