You don't see Z4s very much, but I am also having trouble selling these.
Two 10-foot Monster Cable Z4 Precision Audiophile Speaker Cables with Network Terminators
High-performance speaker cable for audiophile music and home theater systems. Features Monster's patented Time Correct® windings for more accurate music and soundtrack reproduction and MultiTwist™ construction for improved sonic imaging and clarity.
I have them listed at $450, but, again, I'm taking offers -- firstname.lastname@example.org