retail: $380
$100
eBay with Qualitycellz has the manufacturer refurbished LG G4 H810 32GB AT&T Unlocked Smartphone (Metallic Gray) for $100 with free shipping. Listed as 8/10 cosmetic condition.
Snapdragon 1.82GHz Dual + 1.44GHz Quad CPU
Android 5.1, 32GB storage, 3GB RAM, microSD
1440x2560 5.5" IPS Quantum display, 16MP Cam
Meh!
Meh!
Yeah, you can't unlock bootloader on ATT phones as far as I know.
Also, there's a risk of a bootloop.