Do they need to be sealed or have any degree of isolation? Or can they be open backed headphones?
For closed cans, try the Sennheiser HD 280 Pro. For open, perhaps the Grado SR 125. Canal phones are also an option, especially if you will be in noisy environments.
For my part, I am really enjoying my AKG k701's, and these can be had for not much more than twice your budget. They sound so good, I never listen to my stereo anymore.
-Noah