Mercedes key

[mbzman]

I've noticed that my main key was a bit sticky in the ignition as well as door and trunk locks. It felt as if I had to overcome a bit of resistance when I went to use it. I decided to take out my spare master key which hasn't been used at all since I ordered it from the dealer last year. This key works fine in all the locks as well as the ignition and doesn't appear to have the same problem. How long do these factory keys usually last? I believe the one I'm experiencing problems with it only about 8 years old.

I'm a bit disappointed that it is already worn to the point where it does not work as well as it could, especially considering the cost to replace it. Is it possible to get new valet and wallet keys made from the dealer?