I have Sennheiser 580s and LOVE 'em. However, for your friend's application, I would recommend the AKG K240 *Studio* headphones. Be sure to get the Studio version, they have 55 ohm impedance instead of the 600 ohm impedance of the standard versions. These phones play LOUD, have excellent bass, and are extrememly comfortable for long periods of time.
There's a pair on FleaBay right now for $75 Buy It Now with $10 shipping:
http://cgi.ebay.com/AKG-K-240-K240-Studio-HEADPHONES-Mint-condition-55-ohms_W0QQitemZ190037557396QQihZ009QQcategoryZ14985QQrdZ1QQcmdZViewItem
There's a pair on FleaBay right now for $75 Buy It Now with $10 shipping:
http://cgi.ebay.com/AKG-K-240-K240-Studio-HEADPHONES-Mint-condition-55-ohms_W0QQitemZ190037557396QQihZ009QQcategoryZ14985QQrdZ1QQcmdZViewItem