I have a Lightspeed Zulu 3 for sale with case. Only used 3 times, bought brand new from the Lightspeed website directly as a backup headset. I decided that I like the Bose A20 better after all, so i am selling these and getting the Bose for my spare headset. These work fine, but I personally just like the Bose better. Paid $850, selling these for $750 plus shipping.
Wait till you fly something loud! You will want to throw the Bose in the garbage and have that Zulu 3 back.
Sold! They are a fine headset. And I have recommended them to students many times. I just like the Bose better for my head. Planes range from a super loud Champ, to a Cirrus to King Air to Jets.
So you probably won't take $600 for them . . . That was quick! ETA - maybe not. I missed the original post.