The only problem with Sennheisers are that the cheaper ones which are within your budget are suck they only get 3 stars out of 5 for quality and stuff. the Beyer ones got 5 out of 5 and are slightly above your budget, the good Sennheisers start from about 80 dollars, and go rite up to 10,100 dollars, yes no joking 10,100 dollars! Those ones got 5 starts out of 5 and I dought you will go for them. So the best bet are the Beyers, but the choice is yours.. And in the test the Aiwa HP-X222 got 3 stars out of 5 and the comment afterwards was: Struggle to separate instrumental laters but remain listenable - useful 'Mute' button. For the Beyers this is what the comments were: Beyer DT75: Light and comfortable and blend terrific sweetness with good, open, IMPRESSIVE imaging. The Beyer DT231: BEST BUY in the 2000 Awards, Big, RICH BASS that is controlled enough not to distort. Those were the comments given by the best music magazine in the whole of the United Kingdom, What HiFi magazine, and I won't argue with them. But still the choice is yours and go by your own instincts but these are just some guiders to guide you to the headphones you want.
Good Luck,
SKY.