Difficulty: Moderately Easy
Step1
Consider which "first edition" it is. The very first Harry Potter book ever written was titled: "Harry Potter and the Philosopher's Stone." It is far more valuable than a copy of a first edition "Harry Potter and the Goblet of Fire." The latter is significantly lower in value partly because many copies were printed.
Step2
Check to see if it is hardback copy. The hardback edition of a book is of much greater value than a paperback edition.
Step3
Evaluate the condition of the book, which is a key factor in determining the value of a first edition book. The more pristine the condition, the higher its value.
Step4
If it is signed by J.K. Rowling’s, the book is worth far more, even if it is dedicated to someone else.