Random issue w/car starting on 2001 Mercedes-Benz E430

This has happened a few times already so I need to know if this will cause damage to my engine if I don't fix it straight away.
I turn the key to start the car, but it doesn't kick over, like it's trying to but doesn't. But, after a few tries it will eventually kick over/start. Could this be a coil problem? How much does that repair run.

Asked by for the 2001 Mercedes-Benz E430
Sometimes when a battery is beginning to fail it will do this, Maybe have a new battery installed to eliminate this possibility
i just had the battery replaced a few months ago. but i will check the cables and connections just to be sure all is secure. thanks!
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this ened up being the crankshaft position sensors. it was less than $200 to fix (incl parts and labor).