Used Koss QZ-99 Closed Over-Ears for $23

The Koss QZ-99 closed-back over-ear headphones with a mono/stereo switch go for around $40 in new condition at the moment, but you can cut the price almost in half by going used, you can get them in “Used – Very Good” condition for $23~ by Amazon Warehouse Deals. They average 4 out of 5 based on 260+ customer reviews at Amazon.