My understanding of Mercedes keys like what you are describing, they are one and done. They get programmed and they cannot be re-programmed. Mercedes pretty much has people over a barrel on it and as you've discovered, they definitely aren't cheap. So basically, not much you can do about it but pay the bill and get your car out of hawk, though you'll have an extra key for your collection.

My understanding of Mercedes keys like what you are describing, they are one and done. They get programmed and they cannot be re-programmed. Mercedes pretty much has people over a barrel on it and as you've discovered, they definitely aren't cheap. So basically, not much you can do about it but pay the bill and get your car out of hock, though you'll have an extra key for your collection.