40mm - 50mm drivers, heavy coiled cord, solid construction, and a lifetime warranty. Look for all these things for that price and you should never need to buy a replacement set of headphones.
I went for the SONY MDR700DJ headphones... They are 50mm drivers, sturdy as hell, have good bass responce, and twist and turn a million ways so they should never break.
The sony studio phones where weal in comparison and high en heavy with only 40mm drivers. AKG headphones with the detachable cables are real nice though.