The seller was local and had upgraded to an I phone4. That meant he was still with Verizon and the phone probably had a good esn. I called and checked regardless. Just be carefull who you deal with. Work the price out and have them meet you at the closest Verizon store. The store can check and make sure the phone has a good esn.
I think the OP is looking for a phone outside a contract. Maybe he wants a spare for just in case or just to change his phone without lengthening his existing contract. Im looking for the same thing for a just in case situation or just to give it to my bro