I bought these HD-600s new and used them some in my office for a year or so and put them away.
They have no more than ~200 hours on them.

Their reputation is well earned; some people prefer them to the HD650s, and they hold their own well against today's more expensive darlings.
They are in excellent condition. The original velvet earpads are in nice condition, with very little visible wear. There are no marks at all on the headphones. The headband pads are brand new.
The original box is included. It has a bit of damage to one corner. The original cable is also included.
A true bargain for these great 'phones.
Free USPS shipping to Cont. US only.