Your selected Nikon repair service is overcharging, IMO. My 8-year-old copy of the 17-35/2.8, in 2014, had a complete overhaul, including the SW motor, for ≈$450 at Nikon in Los Angeles.
Prices can't have gone up that much in 6 years?
I remember that DPR thread---didn't a later contributor state that they had performed the same repair (getting rid of the squeak noise) without using the liquid metal polish?