The current long distance rate (200mins for $8 & 400mins for $15) is very reasonable for those who use it to call multiple countries that are on the list.
I think PM should separate theses countries and let us pick each country separately with comparable rate other cellular providers offer. On top of that, it is a great market strategy if they offer low rate than other providers. It makes sense since many will see the overall rate when they only call to one country. For example, user just wants to call India. Normal rate from other companies i believe is around 1.5c - 2c per minute. This would be little expensive for them because PM international add-on rate is about 3.75c per minute.
I agree that it is a great deal if someone use it to call multiple countries but not for someone who will call only one country out of 18.