Based on your replies, it sounds like you'd love the Q701 along with a Matrix M-Stage.
It should be easy to find a q701 for around $225. With the price so similar to the K702, it makes no sense to buy the K702 really.
I haven't heard the M-Stage but it's supposed to be a good match for the K702/Q701.
Of course I'd suggest the US built Headroom Micro Amp instead 
Q701 and Micro Amp is probably the best combo I've heard yet, but I did get the HRT Music Streamer II for it.
M-Stage should sound just as good maybe, but I haven't compared them yet and maybe someday.
A used K601 is also a nice option. I'd actually take that (or the K501) over the K702, but not the Q701. Weird, I know.
HD-600 and an Asgard was also a good combo. That's exactly $550.