It's possible that they will release the book by its self at a later time, just as they did with the Jedi Path and it appears with the Book of Sith.
It's also likely that the price will plummet after a few months of release. Amazon is already offering a very generous discount for pre-orders. $51.82 instead of the $99.99 RRP. Considering I used to pay over $40 each for hardcover ST novels to come Down Under, many years ago, this seems very reasonable to me.
I'm happy to support the book at full price, if necessary, since that helps the publisher's confidence for creating future releases.