My daughter uses Calvert. Each year I would like to sell her curriculum to help to defray some of the costs of hs and to make space. Some of the workbooks have writing in pencil. Most don't. When I look online to see where to sell it it's overwhelming. I don't know which sites are legit, etc. Many don't have a feedback system. However, eBay doesn't seem to be the best place. Any ideas? Thanks!