Stu,

What you are saying is that you want everyone who enters to send you a $5 chip, that makes 100 $5 chips for this to work. Then you are going to select the best 10 of these for yourself to cover mailing and shipping. Are you going to send these chips by limo? The post office will do it for less than $5 by priority mail. You need to rethink this. Maybe you could direct each participant to send the chips directly to the winner. I don't think you will get 100 different participants. You may need to let people take more than one box.

How are you going to assign the numbers to the participants?