how much deos fannie mae charge to guarnatee a mortgage?

my credit score is 2 points lower than my mortgage broker accepts so he is doing a fannie mae guarantee. The charge for us is 00.00. Is that standard? the loan amount is about 350,000 on a 500,000 home in NJ. I appreciate everyones input but I am not looking for ways to fix my credit score just about the fannie mae charge and how that works. thanks!!!