This may seem like a lame question but as I am on this page why not ask here.
I have lost my car keys to a Volvo V40. Where can I have a set cut? I understand it's a rather complicated process as they have to be coded when cut. Also can I claim through my comprehensive insurance cover if it's worth it.
I don't think you will find a cheaper alternative, the dealers have it well stitched up on anything to do with auto security.
You might see key blanks on ebay but they don't guarantee that all the key functions will work when they're cut, it might even be that they will only work the actual physical mechanical part of the lock, so you still need to access the security data from the factory data via the dealer for the car to accept it as a valid key, and they won't do that for just a couple of quid and a smile.
My VW replacement last year cost just under £200, if I'd faffed around with an ebay key I'd only have saved about £30.
Your car key doesn't just unlock the doors & start the engine these days, they control the rolling codes for the alarm, and hold data for use during servicing, such as fluid levels & odometer readings etc
Get a fresh key from the dealer or authorised key cutter
Main dealers are usually the first port of call, but they can run out rather expensive.
If you have a Timpson's shoe repair and key cutting store in your area, then try them. Some stores have the equipment for some manufacturer's keys and coded replacements.
You could also ask at some of the local MOT or vehicle repair outlets. They may know a company or person that can make replacements. In my home town, there is one person who can provide the keys and coding for much less than the main dealers do.