OP: I'm confused... You can't find them?
Out of curiosity, I plugged St. Louis into iStockNow.
For AT&T:
St. Louis Galleria Apple Store lists 6+ in stock, silver in 16, 64 and 128.
West County Apple Store has all 3 capacity silver 6+ in stock and has 16 and 64 GB gold.
Or are you looking for a particular color/capacity and that's why you can't find what you're after? Or are you insisting on Best Buy for some reason?
They're out there. Supply is getting better. Unless I'm missing something, to say you "can't find the iPhone 6+" means you're not looking.
Really?! I have been on that site all day and they have had 0 in stock! I have been checking on my iPhone.