How to go about while purchasing collectible books

If you are a passionate reader and believe in collecting books while keeping in mind the factor of future investment, you certainly must be eyeing the best collectible books. However, before you buy any collectible book, you need to do a good research work. The first and foremost thing is the past record of the book. You should try and look out whether the book had generated fare prices in the past or not. Further, you should try and know the popularity and demand of that particular book in the market. This would help you in knowing an apt worth of the book.