Firstly, let me just advise, this is not your typical gaming Art Book, like ‘The Art of..... Uncharted 2, Tomb Raider, Bioshock’ etc. You won't get detailed descriptions from Art Directors/Production team about their concept art, character and environment design.
What you will get is a very polished collection of art by Yoshitaka Amano, packaged to a very high quality level, well above your typical gaming art book. It is expensive, but if you really like Final Fantasy AND art, it is worth adding to your collection.