Need advice for buying c207

I’m currently in the market for a used Mercedes Benz C207 (2010-2014) in Europe and could really use some advice

Finding a model that strikes a balance between performance and reliability while being reasonably affordable to maintain is my goal.

The most common engines I’ve come across are Diesel E220 E250 and E350 - Petrol E200 and E250.

Are there there are any common issues/engines to watch out for or tips to avoid potential costly maintenance.

Thank you all in advance for your help.