I bought one at full retail for $449 as if it were a new plan. Since it's month to month can I not activate it and use it on my old plan to replace my Droid? I didn't have an upgrade.
At full retail you can do whatever you want with it "Activation" doesn't imply a contract. If you paid full price what you will be doing is technically called a hardware swap being you don't have correct 4G data plan though you need to call in. Will ask you to verify your acct like always and then need ESN or number under the battery to activate your device.