But you have always the prerogative to stop and go somewhere if the bounties suddenly chance its payment scheme. So far though, I haven't been in a campaign that changes its payment. But it really hurts if the change of payment happens at the end you have put to much effort and at the end getting less than you expected.

I think it could be serious reputation on the bounty managers, specially if he has built enough trust in the community and probably maybe ruin by just one bounty he manages which suddenly change everything at the end.