Throttle Actuator 1993 300E!! What the...

[pulix]

Got my car back from the mechanic (Mercedes-expert shop) after a routine brake fluid flush and had asked him to look into an idleing problem I was noticing when the car came to a stop. The rev's go Up and Down/Up and Down (from around 1,000 RPM to 2,500 RPM) and ocassionally the car will end up stalling when the gas pedal is hit, (when starting to move again). The mechanic told me it was the throttle actuator that was the cause and laid it down for me!!!!!!! : !$1,900! PART + !$170! LABOR!!!

Please can somebody tell me if I should look into another area of the car or another cause of this faulty idleing, before I completely loose it!!!

Thank you,
Andrew Montoya
Orlando, FL