Yes, if you are replacing your radio with an existing/old radio, there is a $15 fee. However, the second radio (the one to which you want to move your paid service) cannot already be active on any other service (including a trial subscription) at the time you perform the replacement. Nor can a trial subscription be transferred from one radio to another.
Please note: You may transfer an active Lifetime Subscription to another radio an unlimited number of times. For each permitted transfer of a Lifetime Subscription, you will be charged a $35 transfer fee, and the transfer must be effectuated through your Online Account.