Well, there's a huge difference between a bounty, a percentage of the returns and a plain fund which pays regardless of the outcome..
With the recent exchange rate, even a few Bitcoins should go a long way though. I'm in, just to see some justice done.
Ente
A fixed bounty might increase the loss if the retrieved amount is lower than the promised bounty. Same for a fund.
A percentage however includes the incentive to be as effective as possible, because a higher return means a higher reward.