Mercedes CLK or E-Class

Good day to introduce myself briefly am 18 years old, living in Bavaria. I would like to buy a Mercedes soon, but I stand between a CLK 200 or 220 and an E 200 or 220. What would interest me for the first time are the costs (insurance “full cascade or partial cascade”, taxes and other costs that come to me, as well as the split price per 100 km. A cost comparison in relation to the above criteria between a CLK 200 and an E 200 and a CLK 220 between a At the moment I drive an Opel Corsa B with 54 hp and it does not pull :P, therefore the Mercedes. And what is the difference between these two cars. What do I have to keep in mind when buying, how much should the km counter be e.g.? With a friendly greeting NG