I do prefer the black look of the 558s and that would leave me with a little more money for a dac/amp
I know the 598s sound better then the 558s but do they sound €50 better?
They're nearly identical, imo. I don't buy the BS about one sounding better than the other, and there's a piece of foam you can remove from the 558 to make them sound supposedly more similar. Don't worry about not liking Beyer. - I don't care for the simblance either.