Are you talking about AT con itself? There usually is this type of panel on the last day, which (as I understand it) is intended for anything, including cosplay items. This section of the forums is a great place to advertise what you want to get rid of, are looking for, and what others want to dispose of/obtain. I would recommend looking around here; if there are still some things, then this panel is another option. A final possibility could be the charity auction, which also takes place on the last day. This auction is raising funds for the Sunshine Division, which works with the Portland police department to give food and such to needy families in the Portland/Clark County regions.