The appraisal of a gift to the library for tax purposes is the responsibility of the donor who benefits from the tax deduction.
For general information about rare books and determining value, you may find "Your Old Books," (Rare Books and Manuscripts Section, Association of College and Research Libraries) to be helpful.
If the value of the donation is greater than $500, the Internal Revenue Service requires the submission of IRS Form 8283.
If the value of the donation is greater than $5000, an independent appraisal is required by the Internal Revenue Service and the University is required to sign IRS Form 8283 acknowledging receipt of the gift.