Starting Problem 1997 E420 (65,000 miles)

The other day I got in my car and went to start it and it tride to turn over. When I tried to start it a second time the car cranked but would not turn over. The starter now has a differnt pitch to it when I turn the key compared to what it use to sound like. However, it is turning the motor because I can feel exhaust coming out ot the pipe. Could my starter not be turning the motor fast enough? Or is there something else someone can recommend me looking into that could be the potential problem. I would like to way my options out before laying on my back in the drive way and doing a starter since it will be a pain.

Thanks
Pat