There are blogs on the subject of what actually happens with the confiscated items:
and there are a few others. Basically TSA confiscated items that can be resold are being resold through the Surplus program run by the state where the airport is located.
So for example in Pennsylvania Department of General Services Surplus Operations administers such a program, so if you want buy something it would either be at the Harrisburg Warehouse or listed on GovDeals.
Credit:stackoverflow.com‘