Here i made simple with some rules
the donation goal is 0.24BTCs.
When you bid , you state the amount of karma that you agree to get back if you give 0.24BTCs to this donation
the rules:
if you are bidding, you must request a sum of karma lower then previous bidder
If you win the bid, you must wait until the community has donated to the cause all the requested amount of Karma
if the community does not provide the amount of karma requested, the bidder can choose from the following optional rules
Optional Rules:
to not make this a fail project , the winner of the bid that did not get his bidding request fulfilled by the community can choose to accept the current amount of karma that is collected.
If the amount collected is not enough, the winning bidder can decline to collect the current amount of karma collected by the community and ask the to reinstate the bidding.
Once the bidding is reinstated, some one else can bid all over again
in example:
If current bid was 8 million karma for 0.24BTC but only 7 million Karmas was collected , and if the current winner declines to trade for that amount, the bidding is opened again and the next can bid lower than 8 mill and hope the community will fill up the missing amount.