2000 Jeep Cherokee Rear Whell Bearings

I have a 2000 Jeep Grand Cherokee that is at 115,000 miles. The last couple of months I have been feeling some friction from the rear wheels especially when I am coasting. My mechanic informed me that I need a rear wheel bearings job and that it should cost around $700-$800. Does this sound like a reasonable price? I only plan on having the car for a year or two and I'm not sure if a job this expensive is worth it.