Hi. I understand your situation, and I can recommend https://booksrun.com/books/sell . It’s a great service for selling any kind of book, from textbooks to rare editions. BooksRun offers a very simple process. All you have to do is enter your book’s ISBN number on the site, and you’ll get an offer to buy right away. They accept a wide range of books and quickly price them. You agree to the suggested price, ship the books (shipping is at the company’s expense), and after checking the condition of the books, you are paid. I have used this service myself, and I can say that it is convenient and safe. They process orders quickly and transfer money. If you have accumulated a lot of books, this site will help you sell them quickly and profitably.