I've been wondering that for a while, because I thought it would be fun to play with friends up in Seattle. So if you get the exact info, please tell me too! I was just talking to Martin about this. I remember the first part of the 'costs' as:

1 token - yes/no answer
3 tokens - one word answer
(6?) tokens - one sentence answer

then it goes up to 'one paragraph answer', then maybe 'as long of an answer as it needs', and then finally 'a favor', although there were stipulations on the favor, like not costing too much time, or being illegal.