Price also depends on whether you have ASR or not. Do you have ASR? It seems to me ASR cars are much more prone to failure - one rarely ever hears about a non-ASR car having a problem. There isn't a code that says "your throttle actuator is bad" so beware of anyone that tries to make it sound that simple - they may just be seeking your $2400. There's lots more information in the archives here, do a search above, and here: http://pages.prodigy.net/jforgione/MB_S500.html which is a car with ASR.