It would be delicious to call up everyone you owe and say, “Cut me a deal,” and have them respond positively.

Greece has been furiously working on just that. It’s an effort to save around $126 billion on what Greece owes investors in its government bonds. Throughout the day, there were reports that investors would get just 50 cents on the dollar, a “haircut” not for their heads but their wallets.

But, even if Greece and the Institute of International Finance (the group negotiation on behalf of the debt holders) reach a deal this weekend, they are not out of the woods yet.

Ben May, a European economist at Capital Economics in London, says, “The real issue will be how many of Greece’s creditors will participate in that deal.” Some creditors will prefer to take insurance payments that kick in only if Greece involuntarily defaults. May says it’s “a funny situation where some Greece creditors will want the deal to fail.”

May says Capital Economics has already modeled out a 2012 in which Greece opts out of the eurozone. Ireland and Portugal could follow next year. For now though, it’s all about bargaining, and the Greeks need to reach an agreement fast to get things lined up to receive the next round of bail-out money from the European Financial Security Facility. There’s a $18.7 billion tab coming due on March 20.

It’s going to be a long weekend in Athens.