I am not 100% on this but I also remember something about there being a transfer fee if you want to have it in your name etc for all the speedhive functionsEdit- the transponders do have some value without a subscription, as renewing a unit is cheaper than buying a unit.
It appears there is a small difference, apologies for misleading. Saving the 30$ a year, to me anyways, isn't worth dealing with used equipment.