If you have the Scenic one then the key is bladed and you do not need to get one from a dealer. You can buy the blades and transmitter sections on e bay.
However you then need to add in the cost of cutting the blade and getting the key coded to the car. Obviously Renault can do the coding but an independent auto electrician may also have the right gear for this.
many thanks for your reply ill check out
and find local auto electrician..many thanks