dont do it. youre not going to sell 500 tickets at 200 a pop, and youre gonna hit legal problems. timeline? people are going to want one, and do you wanna be refunding money? and no, unlike what the one person posted, you cant sell "more" tickets for charity, youll affect the original odds and break the contract you made with the original buyers. think about it. i buy a 1/500 chance than find out you sold 700... you will be hearing from an attorney giving all your money away.
this is a stupid idea outside of an audited fundraiser. just sell the truck.