You might wonder why car keys can be expensive to replace. Anything from 1990s onwards will be more than just a metal key. There will be a form of additional security such as immobiliser/transponder. Some car keys can be programmed easier than others. Many vehicles can be programmed just by plugging in specialist computer. Higher end and later vehicles can require complex procedures to produce a working key.
All keys lost for later Audi, Mercedes, Land Rover etc can be complicated. Take BMW keys for example. In an all keys lost situation it requires removal of the FEM/BDC as well as the ECU from the engine. In some cases it requires de-soldering of components off and on the circuit board. (Older versions of BMW use CAS/EWS systems which also require removal from the car).
An independent auto locksmith will normally be much cheaper than a dealer. A customer we helped today had lost the spare smart key for a Mitsubishi L200. They’d been told by the hire company it would be over £600 to replace it. (We charged a fraction of that). A lady customer was quoted £600 by a dealer for a simple chipped key for a Suzuki swift. That’s a ridiculous price. Fortunately they came to us instead.