I currently have the hd497s and love them. However, my roomates are annoying and listen to horrible music. I need a good pair of noise cancelling headphones, pherhaps splurge a little bit and buy an X-fi with my new system as well as the said headphones.
I may even go a bit beyond the $50 range, if you guys assure me the benefits will be incredible and I will listen to all my albums in new bliss (and drown out the metal and jpop in the background).