I'd say the mileage is a bit high. I've heard these cars can go 200k if well maintained. If you're serious, make sure you can get a detailed history of the car (# of owners etc).
But I'd keep looking if I were you. I looked at 3 CLK's before buying mine and with each one I was real indecisive and posting here a bunch. Once I found the one I just bought I knew it was the right car instantly. If you're patient you will find you're dream car.
Problem with CLK55's is they aren't abundant on the used market...but that's what makes them great too

I probably see 1 on the road a month and I live in a large metro city.
Good luck!