bad wheel bearing?
 

Apparently my right wheel bearing has gone bad. Whenever I apply brakes I hear a pulsing squeeking sound. GM tells me I have to replace the entire hub since it is a sealed bearing. The part is 500 dollars.

Does this sound right? What should I do? How hard is it to replace that part?

I replaced mine on my 97 camaro and i got the whole hub from the junk yard and their is 4 bolts on the back and switch them out. just remove the brakes and everything. The only problem i had was the abs sensor was bad so check the abs sensor 1st. overall it wasnt that hard

149.99 at ecklers, I am sure a sponcer could get it as well, like he said 4 13mm bolts I would take to steering tie rod off, to allow you to turn it (hub carrier) by hand, remove the bolts and smack the old with a 3lb sledge all around till it comes out, sand the opening slightly and reinstal the new one.