It's hard to tell for certain, but the one on eBay looks like it's the same as one of the guides I have. The cover 's identical, but I can't tell from the picture alone if they're the same size or not. The ISBN for mine is 4-575-16328-7, and it's about 5 3/4 x 8 1/4 inches. (You might be able to ask the seller for the ISBN.)
If they are the same book, it's a pretty complete strategy guide. I used the Dengeki guide (ISBN 4-8402-1937-0) more, but I didn't think either one was bad.
I don't know anything about the one on Amazon, unfortunately. It's also listed on Amazon's JP website (just search for the ISBN), where it has a one-star review. My Japanese is really shaky, but I got the impression from the review that the guide doesn't cover the entire game.