Used Sony MDR-7502 for $18 plus S&H ($3.75 or more)

More used action, also at Adorama, you can get the Sony MDR-7502 Closed On-Ears for $18 plus shipping. The lowest appears to be $3.75 regardless of zipcode (at least among my “test zipcodes”). The headphone weight is 5.1 ounces, so lightweight and not taking up too much space can keep S&H fees down.

If the used inventory sells out, you will no longer see it at the above search results. Their individual product links have a lot of empty spaces (four in a row) which can confuse some browsers (and definitely confuses my html editing), that’s why I am linking to the search results instead. As of the time of writing, the 7502 is third in the search results above.