Currently using a Verizon Lumia 928 and getting sick of using my personal phone for dev use. I noticed I can currently buy an AT&T Lumia 520 with a bad ESN for around $20. I understand that bad ESN devices are either stolen or linked to accounts that have large unpaid balances. However, do carriers lock out any other features on Windows Phone devices besides reactivation? I'd need the new device to utilize WiFi, USB, and link to my Microsoft account. Has anyone else gone down this road before? Thanks in advance for your advice.