It seems that the fate of the prize money is having a huge effect on people's choice to cooperate or defect. Yavin could modify the numbers by some potentially large percentage by offering to either donate the remainder of the prize to a charity, or to do something near-equivalent to burning it.

I chose to cooperate because the good feelings are worth more to me than a fraction of a cent, and I expect people to prefer cooperation even if it is the anti-game theory response.