According to this video, there will be at least 80 iPhones per AT&T store in the USA. The store in the video is in the South*. So I'm assuming large city stores à la New York City and Chicago will get many more. This kind of jives with the ball park figures I calculated. Note there are at least 80 iPhones is this video. There could be many more.
*I know the accent isn't from a big city. Anybody know exactly where it is from though?