Ahhh, so there's the rub. I didn't think about the shipping. In effect, you would be paying someone to take this stuff; not kosher. Personally, if you offered to give me something cool, like what you have here, I'd probably be very happy to pay the shipping on it. Tell you what Colin, I'll help you out. Pull the heaviest thing you have out of the swag bag and offer it to me. I'll bet I'd gladly pay the freight to get it to me (probably have to shell out a bit of change for Mr. O and his customs minions as well).
Seriously though, I don't think we'd mind paying the postage on something you want to give away. Just make that part of the offer when you notify the winner, or at least ask for a donation to help cover the costs. And, if someone is going to shell out real money to participate in a charity raffle, unless you pull in thousands of dollars, I don't think they would mind picking up the shipping as well to get as much coin to your charity as possible.