Can I sell a brand new unopened iphone 5 on Verizon even k ow I owe them money?

I was gonna upgrade 2 days before my bill is due and get the 5 but I'm switching carriers and not actually paying the bill, can I sell the iphone 5 unopened? Since the phone on Verizon is unlocked will it always have a clean ESN?

It will be locked to the phone number you upgrade it for. Once your account is shut down for nonpayment, it will be flagged and the ESN will not be usable until you settled your account. When you are sent to collections, the phone becomes a permanent paperweight.