How do I do a banquet for charity so that it doesnt cost me a fortune?

I have recently started a volunteer group that is made up of about 100 cheerleaders and their families. I would like to be able to raise enough money to buy a goat or cow for "Heiffers International"(This is a non-profit group that helps needy families in Africa with the purchase of farm animals). I need to raise about 500.00. The problem is that I personally have 0 dollars to start. Any ideas on how I can raise money in a fun, inexpensive way?? Help, Thanks