I am not using the Cayin HA-300 anymore, this amplifier has a phenomenal sound, I have used this amp with ZMF Aeolus, Verite Closed, HD800, Susvara and many others, all sounded great, some better than others. The one thing I can say about this amp is you don't need exceptional headphones to get exceptional results, I would rather run a better amp and know that I will be getting the best out of my mid tier headphones! Anyway, there are great reviews on here and the web to back up my impressions. I am thinking 3K plus shipping and fees. I have the original box and packing to ship safely. Send me a message to discuss.