Well the lot certainly was not cheap..lol
My understanding is movie watches were indeed made by Patek Philippe - maybe using different materials, so these wouldn't cost what an actual "store bought" one would cost..as these were to be worn during action sequences..it wouldn't make sense to destroy an expensive one.
Also not very clear in the photos but movie watches were also deliberatly weathered to look old and well used. I was able to closely examine 2 x screen used ones..and they were very similarly distressed with only minor differences.