As stated above, New lenses imported by Nikon USA include a one year international warranty and a four year Nikon USA extended warranty for a total of five years of warranty coverage. As you know, refurbished lenses include a 90 day warranty.
You have to decide is the $300.00 difference in price worth the peace of mind of having 57 additional months of warranty coverage.
While Nikkor Pro lenses are extremely reliable, when ring motors fail, they are expensive to repair.
There are many here that have purchased refubished lenses and or cameras and never had a problem. Others have had problems. That said, on very rare occasions there have been issues with new lenses.
Again, only you can decide if the savings is worth the added risk. Good Luck and Enjoy your Nikons!