Bookstores are going out of business because people are not reading books as they use to. Now many people read via e-books which they download. The books you have religious and have a small market. The Reform prayer books are only good for another Reform synagogue and they as a movement are dying out with their synagogues closing or merging. The reason you got them in the first place is because the Reform synagogue couldn’t find a buyer.
In Brooklyn, NY Jewish Orthodox used books such as the Talmud are sold in the back of stores and on the street for between $1-5 per volume just to give you an idea of the marketability of used religious.