That ebay add is no bargain. You can get a Cardone rebuilt MC form Advanced Auto for $20.
My experience with Cardone remanufactured MCs has been good. The original drum brake MC on my Barracuda was replaced in 00 with one. I used it until 03 when I swapped in disk brakes and picked up a manual disk MC and that has been in use since 03 which equates to close to 50K miles.