Get a few $5 giftcards (maybe even some donated) from a local coffee shop; a coupon for a free car wash, a free sandwhich for a local fast food place (Chik-fil-a is a good source), etc. You can sell the "donation" by saying that you're asking for a small amount to get a customer in the door and the person will likely buy something else. these are little prizes that aren't expensive and can be used by the individual or passed on to a team member. I lucked out and found some cancer ribbon ornaments at Marshall's and used those for the team that increased membership by the largest percentage since the last meeting and another for the team that has raised the most per team member.