That is a Beretta 92SB, a fairly rare and highly desirable variant of the Beretta 92.
Personally the 92SB is my favorite handgun, and I've owned many high end pistols.
A fair price for a true NIB, or Like-NIB example would be $800-$1000. (I've actually never seen a true NIB 92SB)
I paid $850 for my Like-NIB Beretta 92SB, and for me personally it is a fair price.
I also paid $650 for another 92SB that has slightly more finish wear... it really depends on the seller and how bad you want it...
The one in your picture seems to have a after market Pacmyr grip, a non-factory extended mag, and a non-factory standard capacity mag.
I highly doubt it is a true NIB pistol, but from the one picture you provided, it seems to be in excellent condition with slight wear on the front edge of the slide.