It is relevant to note that the spread on ten year Irish Government Securities above Bunds immediately after the end-March 2010 PCAR announcement, that made it clear (to any that still doubted it) that extremely large banking losses would be incurred by the banks in the NAMA purchases, was only about 125 basis points.
Clearly, the cost of refinancing the amortisation payments at such a yield would have been much lower than it is today. The first annual amortisation payment was made in March 2011. (I abstract here from the question of the interest holiday for the first two years).