The borrowing rate on the European bail-out fund (the €440bn EFSF fund) is less than 3% . The reason is that If all 17 eurozone nations worked together and borrowed money as a group, then the weight of the larger and more creditworthy among them would mean a lower borrowing rate (interest rate). Six eurozone members have excellent AAA credit ratings (including the EU giants France and Germany) and they therefore borrow at a lower rate than the much smaller, high debt nations like Greece or Ireland.
Of course, this means that smaller eurozone countries ‘piggyback’ on much bigger nations credit rating to solve their own problems which isn’t viewed as very fair if the bigger countries have to then pay a higher interest rate collectively than they would have on their own. This is why French President Sarkozy and German Chancellor Merkel constantly have to walk a politically delicate tightrope to get agreement on any united European effort.