Hey Spammer!
From what I understand, you want to organize something like anonymous "people's CIA"? right?
If yes, then your "PPI" system is too complicated.
All you need are simple wishlists:
***
I would donate for:
mission - price
mission - price
***
"Agents" will track user's lists and fullfill the highest paying missions.

And there is absolutely no need to waste money!
User can demonstrate his/her determinition to pay by making donations to well-known charity organizations.
For example, every month: pay for completed missions - update and publish new wishlist - make small donation.

(...but, if you really give bitcoins, here is my address bc1qgrh4pvj0lhf0nm264sppuwa9l8pc6q2tys0vgc)