While comparing Nikon 85mm f/1.8G and 50mm 1.8G, I found the former to be quite a bit costlier. The differences, as I find, are obvious ones because of the focal lengths, e.g. angle of view, dimension, weight etc. All those don't apparently justify for the higher price tag. Is there any crucial/must-have feature the former offers which the later doesn't?
The 85mm requires bigger glass elements to be able to offer the same aperture f/1.8 as a lens with a shorter focal length. This alone makes it cost more.
In addition, it becomes heavier so it also needs a more powerful focus motor.