Honda Civic and C200 are both compact cars so it's not much of an upgrade unless...
Bragging Rights are high up there in your list of agendas in which case; I seek your forgiveness.
Anyhow; maintaining a Mercedes is going to cost you a hell lot more than a Civic; especially if the car is a decade (or more) old. Mercedes, BMW and Audi aren't exactly known for their reliability and cheap as chips maintenance, you know?
A used 8-10 year old C200 in decent condition goes for about 3 millions. And I'd rather have a 2-3 year old Prius than a decade old Mercedes that's going to spend the majority of its lifetime in a garage!
And did I mention that Prius is way more reliable, way more spacious (It's a mid-size sedan) and returns fantastic fuel economy that's comparable to my 2-Stroke 100cc Yamaha?
Up to you, my dear.
Good Day!