If you have 2 keys that start the car you can programme the new key to the immobiliser yourself (process in handbook)

If you only have 1 key then it will need to be programmed on WDS at roughly an hours labour (depends on dealerships labour rate)

The remote key £65.38 inclusive of cutting, battery etc
Manual key £21.84 inc

If you need the remote programmed to the C/L if your dealer is helpful enough they should be able to tell you of the process (quite simple to do)