2000 Range Rover 4 cyl Four Wheel Drive Automatic 98,000 miles

Hello,

I have been told my Rear Differential Assembly needs to be replaced. I have a 2000 Range Rover with 98,000 miles on it. I have been quoted a price of $2,500 from my dealer to complete the job. Is this price reasonable? How much are the parts for this kind of service? Is the job that labor intensive? Am I being ripped off? Help! Thanks.