@david
dont pay the extra! A new vehicle on the road price includes the plates, if the dealership has done it properly then they don’t need to change plates just have yours made ( instead of the normal individual plates)
i would be wary if they are trying to charge as it would indicate the vehicle is already registered. The £80 is DVLA transfer fee which is to be expected and normal, I’m guessing your taking an in stock and pre registered car and they are trying to pass on the cost.