Followup question for the comments below.....Let's say the bounty campaign ran for two months with a budget of $450,000. How many participants should be accepted to make sure all participants were paid generously?
Do you mean $450,000 is only for 1 bounty or some bounties?
Many (Almost all campaigns) has allocated their bounty amount to some bounties (i.e signature, social media, blog/media, translation bounty) with difference allocation of bounty.
Also, what's can considered will be paid generously? above $500 for each participants? Just fyi, almost all translatior would be get paid at least more than $2000 in each of translation (If you looking it more carrefully, there was a campaign has paid $100,000 to their translator).