As other people have been trying to explain, the watch shops and kiosks all keep the worst reps in their stalls. If the shops are raided, only the junk is confiscated. If you go to the GZ shops, all you will see is junk.
You have to begin bargaining with a shop keeper and explaining over and over that you want the "swiss machines" ... and then maybe they will send a runner to get a good watch from their locked rooms.
From the way people describe the experience, it's tedious and repetitive, and you have to have the balls to haggle in an extreme manner (get up and leave then come back etc) to get a fair price.