Why so many headphones for sale with less than 10 hours of listening time?

Hi guys any advice amp related to make the HD800 shine?
Thanks 

I read a review of several premium headphones by Herb Reichert in Stereophile a few issues back. He tried out several of the big players and was pretty consistent in mentioning how deep into the music this new generation of headphones can be. When he got to a pair of Audioquest Nighthawks, they sounded dull and closed in. He called AQ to find out what's up with 'em and they said the 'Hawks need serious break-in time. So Herb let 'em run in for several days I think. When he put them back on for a listen, they became one of his favorites of the bunch he reviewed, and they were near the bottom of that bunch's price range. 

Ten hours is not nearly enough, and headphone diaphragms have tiny, delicate movements. It stands to reason that just a little bit of suspension stiffness could really make them sound dull and uninvolving.

Johnny- that has been my experience (with break in) and one of the reasons I started this thread.....to see if anyone else noticed a difference after a long break in period.