Try the iPad Apple Store app rather than the iPhone
I have been trying since 3am with the Apple Store app on my iPhone. I would get to the point where I chose the configuration and it said available for shipping Sept 19-23 but no buy button would appear. I finally started trying with the iPad app and after choosing my config a button with the price let me click it to move forward. The phone is still not letting me do it. So very odd! Oh well, done at last. iPhone 6, Space Grey, 64GB, Canada. Says delivery 19-23.
I have been trying since 3am with the Apple Store app on my iPhone. I would get to the point where I chose the configuration and it said available for shipping Sept 19-23 but no buy button would appear. I finally started trying with the iPad app and after choosing my config a button with the price let me click it to move forward. The phone is still not letting me do it. So very odd! Oh well, done at last. iPhone 6, Space Grey, 64GB, Canada. Says delivery 19-23.