AWD Rear Differential Replacement on 2006 Toyota Matrix

My AWD Matrix was Towed in NYC, and after that there's been a whining sound coming from the Rear, when going 20+mph had a local mechanic checked it out and confirmed it was coming from the rear Differential. the quoted price for parts and labor was $1700. sound fair? please let me know..

Asked by for the 2006 Toyota Matrix
Depending on the noise, there was a bulletin related to a rear diff. noise on the rave 4's
which required replacing the fluid which was modified from Toyota. This could also relate to your Matrix.
No... took it to another place they changed the oil in the diff. sound was still there... they didn give me a price only refer me to another place... Im about to drive around and try to get another quote for the price...
This same thing happened to me with my Matrix just this past week, but the estimate I got was 2700... where were you in NYC that charged so cheap??