The institution, the building, and the people of the Beinecke
Yale University policy prohibits librarians and curators from providing financial appraisals. Professional appraisers and booksellers can authenticate and evaluate your books and documents.
You might try contacting a book dealer belonging to the ABAA http://www.abaa.org or ILAB http://www.ilab.org if you are interested in finding out more about the value of the book. For general information about the value of your book, you may also wish to read a publication of the Rare Book & Manuscript Section, a professional society, "Your Old Books," which is available online here: http://www.rbms.info/yob.shtml.