Gah! I want Vanellope. I may be looking to set up some teams on this effort. I did it once before and it worked. Everyone signs up with what pin they want. Then you agree, with public shaming as a consequence, that you will sell the pins you don't want, at cost to anyone who does not get the 1 pin they want. For Example.
Group 1:
Vanellope - Mark Wants
Olaf - Member 1 Wants
Russell - Member 2 Wants
If at least 1 of the 3 people gets a good number, everyone gets their pin at cost. If 2 members get good numbers, the 1 who did not gets to buy the one at cost from one of the 2 members and the other member sells them at cost a pin. (In this example, lets say Mark & Member 3 get good numbers. Mark will sell Member 1 Olaf at cost, and member 2 will sell Vanellope at cost to member 1. So Everyone gets the pin they wanted and noone gets 2 of the same pin.) If all 3 get good numbers, everyone wins. Make sense? (Expanding on if 2 get good numbers, you just rotate the pin. So if Member 1 & 2 both get good numbers and Mark doesn't, Member 1 sells me Vanllope at cost and member 2 sells me Olaf at cost. That way everyone gets 2 pins, everyone paid cost and everyone got at least the 1 pin they wanted. But you have to agree going into this that you will sell at cost to anyone that does not get a number. It works really well when you can find 3 people that agree they are only there for 1 of the pins.
Also, any surprise pin is kept by whoever gets the good number.