Personally I believe it depends on what you will be using them for. If your using them for music then ath-m50 would probably be much much better and totally worth it.
If you mainly use headphones/headsets for gaming or movies I would definitely stick to the gaming headset as it has a mic + most of them have surround sound.
Alternatively you could spend a little more and get a nice open back like the sennheiser hd 598 headphones which would be good for all 3.
Possibly the other 5xx sennheiser headphones would work too and the 518 are near your budget. The only problem with those is the fact that they are open back so if your in a noisy environment they wouldn't work too good but if you game alone in your room or something I would recommend them over both.