2003 Mercedes Benz C230 runs like it is out of gas hesitate

Although you have pretty low miles you may be experiencing a faulty fuel sending unit (fuel pump). This will cause the "out of gas" experience you are having. Also it is not uncommon for things like this to not throw a check engine light. Often times problems like these will require some electrical diagnosis to figure out what component is ultimately to blame. Also a faulty Mass Air Sensor may cause a similar condition and is closely associated with throttle response.

I absolutely agree that you don't want to throw parts at this problem because it will get real expensive real fast. In this situation what is necessary is to be able to read your mass air flow sensor values in real time, this will require some pretty sophisticated scanning equipment that can read values while the vehicle is being driven. I know this is possible with the MB Star diagnostic tool which is what your dealer uses and has the capability of reading multiple sensors at once. As for the fuel pump you can hook a fuel pressure gauge up to your fuel rail to check for proper pressure but if you are using good gas a fuel pump will be more unlikely. As for the throttle position sensor, this is typically associated with no throttle response and not the bucking and jerking you are describing. Usually what will happen is when you hit the throttle nothing happens or you get a delayed response from the motor. Personally because of the intermittentness of this, I would recommend taking this to a dealer and tell the service advisor exactly what is going on. Then ask him to have a technician ride in the vehicle with you so you can duplicate the problem for the tech (this will prevent them for sending you home with no problem found). Once you have shown the tech the when and how the problem occurs the tech will have a complete understanding of the issue at hand and will allow them to diagnose the problem without trying to duplicate the condition on their own. A dealer will have the ability to read the real time values while the vehicle is driving and when the condition occurs. This will allow for proper diagnosis without throwing parts at the vehicle.