Sonix Elecronics has several headphones, amplifiers, and accessories (open box or used in various conditions) in its "liquidation station": https://www.sonicelectronix.com/cat_i354_headphones.html?ls=1.Do I remember correctly that Sonix Electronics is leaving the headphone market? If so, they will be missed.
Deals on the open box Grado SR 325e at $149 and Beyer T1 (gen. 1) for $450 are worth checking out.