Late 2013 W204 cars, and all 2014 W204s, will have the M274 engine (for the C180), and do not suffer subframe issues. They'll be cheaper than the W205 - but then the W205 is the newer model / nicer car.
I guess what I am trying to say is that if opting for a car from mid-2013 onwards, then you can ignore M271/M272 engine and subframe issues, and simply base your decision on budget and model as you normally would.