its a 2000 C230 - and the ads on ebay say the KEY FOB - can be reprogrammed to start the car - because the actual key part doesnt start the car - its the FOB that turns the ignition.
Um, yeah, I know *exactly* what you're talking about.
Have the guy on ebay give you a specific place where you can get it reprogrammed, because there isn't one. He'll tell you any dealer or some such stupid nonsense. Call your dealer. Call MBUSA. Call NASA for that matter. Believe it or not, sellers actually lie on ebay sometimes.
If you can't find someone to reprogram it before you buy it, you won't be able to find one after, either.
There are several hundred threads on this forum on this exact topic, and not one person has ever been able to get a used key reprogrammed.
But hey, don't believe me. The longer you dink around before calling the dealer to arrange to order one, the longer you won't be able to drive your car. When you get to that point, you might ask if they'll give you a discount if you buy two, then you at least will still have a car if you misplace one in the future.