it sounds like a wheel bearing to me and its a common problem, its a sealed bearing assembly and they usually run in the 100 dollar area, maybe a little more pending on the bearing you get. there are easy to check and do. jack the car up and roll the tire, it might sound like theres sand in the bearing, makes a kind of grinding noise. also grab the top and bottom of the tire and try moving the tire up and down. if its bad youll feel some play or looseness in the bearing.
they are pretty easy to replace too. take off your caliper and mount, pads and rotors and remove the 3 15mm bolts and the axle nut. then its just a matter of getting it out of the spindle. use plenty of knocker loose, and a hammer chisel, pry bar, and a beer may be necessary to get it out if there is some dirt and rust in it. also make sure when you pound the axle out of the bearing that you use a dead blow or soft hammer so you dont damage the threads on the axle.
