Instead of making it just for Christmas, why not make it a permanent lottery event. Like players can exchange tokens/zenny to ticket and every end of the month a raffle will be drawn via random script.
Example:
X number of tokens = 1 ticket = 1 chance to win
or
X number of zenny = 1 ticket = 1 chance to win
Prize:
1st winning ticket: X number of tokens or ?
2nd winning ticket: X number of tokens or ?
3rd winning ticket: X number of tokens or ?
In each player account, we can view the ticket/s number that we purchased and in the forum the winning tickets and players will be displayed. Winners can claimed their prizes through an NPC.