I agree don't start throwing money at the problem.Try to diagnose problem and test parts before buying new. If the engine starts and runs good untill it's warm, than check things that are not common to cold start. I am not a MB mechanic, but reading threads on this forum can be very informative.
Learn about checking Idol Control Valve , EHA current , Duty Cycle, Adjusting fuel mixture, etc. With a knowledge of how the engine operates and a few inexpensive tools you can fix it without buying parts you do not need.
Jeff