Recommendations for a sub $1K FX portrait lens

Another vote for the 85/1.8G.  It's light weight, small, fast focus and one of the best value in Nikon's current line up. The rendition is a bit on the cool side (compared to 24-70/70-200) due to lack of nano coating. 105/2 or 135/2 DC are even better lenses if you don't mind not having AFS.

My other favorite is the 70-200 f/2.8G VR2 at the 200mm end.

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D800E
Nikon Zooms: 16-35/4, 24-70/2.8, 70-200 VR2, TC-20E3, 28-300VR.
Nikon Primes: 24/1.4G, 50/1.8G, 85/1.8G.