Price should look something like this: http://imgur.com/a/1V3yb
I'm not sure what else needs to be said about these headphones. They're awesome, I like them more than the HD 700's.
They're 300 ohm headphones but they're not that difficult to drive. They'll sound good with just about anything. But obviously they'll sound better, with better equipment. That's one of the beauties of these puppies. I personally have them paired with an iFi Micro and they sound really good. I've heard they go exceptionally well with tube amps though.