To improve your chances of getting full credit, provide a sales slip or gift receipt, return the item in new condition, unopened, and with all packaging material.
The Preferred WeGoLook service includes the Looker providing his or her general observations about the basic external cosmetic condition of the item (looking for the presence of obvious chips, cracks, dents, etc.) and report those observations to you.
Employees will decide if your wares are in decent enough condition to sell, create a listing and, if the item is sold within 14 days, split the proceeds between the "seller" and Goodwill.