When we cruised on our Merrytime cruises it was free. Sign up was at Guest Services. I remember that I headed to the special off-the-side area on a different deck for Frozen meet and greet tickets and sent either my husband or older daughter to get the gingerbread tickets at Guest Services. We really enjoyed it and my youngest ate that house for what seemed like DAYS! Try to do it early on so that the gingerbread house can sit in your room as long as possible because you can't take it off of the ship with you!