I think the Sam's Candy Bars are a great thing to sell- a dollar a piece is easy.
Another thing I did (back in the mid-90's) was stand at a busy intersection in uniform holding up signs that say "send us to XX" (the junior olympics, or state tournament or whatever). Back then we made about $40 per hour per person- it was great! We even had police officers voluntarily park near us to make sure no one bothered us. I know money is tight for everyone now, but baseball teams around here still do it all the time and it always looks like people are handing them money.
As long as you don't mind the shameless begging you could do well! Back when I was a kid that was the only way my family made it to the AAU Jr. Olympics.