Usually £24.46 and available with free instore collection.
Probably works out about the same price as having 2 new keys cut.
This Yale door lock is designed for external doors comes in a modern chrome finish complete with a bolt hold back. It is made from brass and is designed to provide ultimate security as well as sympathetically blend in with your existing door furniture. 2 keys are included to operate the door from the outside and a knob handle to operate the inside.