The title of this post was so unique that I had to go at Amazon and look for this book. Found it.
What's in this 100-page-low-yield-subject book that makes it worth $400? Apparently the reviews are great, but still, I'm curious? Has anyone ever used it and managed to get a 270 or 260 on step 1?
sometimes the book sellers will price a book very high even though the book is not worth it because people who are stressed out will pay any outrageous amount out of desperation.
as far as the subject embryology is concerned, I seriously doubt for step 1 that you will need more than what is taught in the question banks,
also do know what is found in the book First aid for usmle step 1.
if you want to do well in school, study your school's notes, then go through question banks or kaplan lecture notes with videos or brs for that particular subject and wikipedia. Lippincotts illustrated q and a series is newer to that expensive embryology book and probably much more useful.