I don't think it's that much. Kleeman is an exclusive upgrade shop for Mercedes. Since the motor is the same. I've heard of 11k for a supercharger for an slk. I wouldn't think it would be more than that. While not cheap it will get you some pretty good power and Kleeman stands behind their products and installs. As long as a kleeman certified dealer installs it. I've heard of many people shipping their car out to Colorado Springs so Cory, at kleeman, can do the install himself.

http://kleemann.dk/site