I think the cleanest way to do it would be to simply decide before when you were working out the split the humi is going to end up being X% of the price. If I were managing the effort then I'd simply commit that "gang we're not going to go over $x for the auction." Then everyone commits thier funds based on that price. "I want 10" kind of thing. If we buy for less than X everyone gets a price reduction across the board.What do you think the humi itself would be worth?