I don't have that much experience, but from what little i have by the time the feeling is that obvious, the culprit for anyone who knows anything about car is fairly obvious too. I know this isn't always the case, but still worth jacking up in the air, taking the wheels off and looking at the bushings, joints, drive shafts (cv joints) and tie rods. Then if he can't see anything, take it in somewhere. From what I can tell he hasn't even tried to find the problem other than having the wheel's balanced (which I think should be the first step, by he needs to take the second one).