I dont have anything, I just think other options are more viable (planar et al)
I will bet you a cookie its not on the Sea of Fallen Stars (although that would be neat).
I don't think we will get Planar until planescape and spelljammer setting come out IMO.
I am not sure how I would get a cookie to you if I lost honestly, if I mailed it I would not suggest eating it, especially if it's green.
How about the stakes be a point of experience, the one who loses the bet has to give 1xp to the winner.