How often do you check? I’ve heard Sundays and Mondays aren’t the best days to check, but it only took me maybe 4 or 5 days with checking like 10 or so times per day for me to catch a Sierra blue and graphite 13PM both at the same store. Fortunately it was at the store closest to me to, but I was prepared to drive 1.5 hours
I know some people have automated python scripts to alert them when they become available. I think the details on how are in this same thread. I just used the
https://iphonechecker.herokuapp.com/ method though.