Latley the past few months ive noticed a noise from the rear passenger side wheel

, I can hear it in the car while driving and it gets faster as I accelerate its like a rubbing or grinding type noise. Someone told me its a bad wheel bearing if so how much are they, and is there 2 (inner and outter) and how hard is it to do Im alright with tools ive always done all my own work on my car and would like to attempt to take care of this. Any suggestions would help.