I am driving a 2008 G35X with 160,000KM (100,000 miles). My dealer recently told me that the steering rack is leaking. I asked how badly and he said it's minimal - not sweat, but a drop occasionally, but advised that it will likely get worse. As the only solution he recommended replacing the steering rack and quoted me $2750 for the entire job. Two questions: is this an issue that truly cannot be fixed and steering rack needs to be replaced? and am I getting ripped off on that quote?

If the rack is leaking from the seals, there is no other option but to replace it.

Guessing by your KM measurement you are in Canada? 2750 CAD is about 2100 USD and that is inline with what most dealerships charge for this repair.

I had an independent shop give me a quote and it was 1000 USD. You can either get new or refurbished racks (the independent shop quoted a new one), the latter for which would probably bring the price down even more.

Yes, definitely get a quote from an independent shop. Check around for recommendations for honest shops or call AAA or CAA for their rated shops.