Dubstep may be like instrumental rap and hippity hop. but i dont think headphones with muddy bass is something for anything.
I own the Sony XB500, a great can for its value; though, i think they are really bassy... too bassy... its SS is not in my taste but they're a fun can to listen to if you can manage the bass.
another gem i like is my Sony MDR-V6, i think this is best suited for you as it is ALSO great for the money. people state its Bass is not too muddling, and more in a musical bass like.
but i really like listening to Dubstep, DnB, Trip, Glitch, junglist, etc with these cans. nothing is too drowned out so you will hear a good layer of music.
though i can tell you to trust buying genuine MDR-V6's at Amazon.com under the dealer: AmazonLLC.
the 2 cans i listed are both great for the money, best under 100$! and im sure many people will understand here.