Thanks to being GSM models, AT&T are in hot demand all colors and sizes.
I see that the wifi ones especially 32GB and lower capacity are selling well in South Jersey, as all the Targets, Wally's World, and Best Buys in a 50 mile radius are always sold out, expect, when a limited availability pops-up and it is quickly bought.
The Verizon ones are the ugly sister of all 18 UPCs/SKUs because they're CDMA, I really wanted AT&T, but 90% of my travel is to Puerto Rico which has CDMA coverage, I "settled" for the 64GB White Verizon model.