Value Increase of Certain Pop-Ups!

I am a new collector, so forgive me if this is a silly question, but I couldn't help but notice that there are some pop-up books out there that have doubled and tripled in value in a relatively short amount of time. "The Pop-Book of Phobias", "Wicked the Musical Tie in', and "Alfred Hitchcock" were the ones that have really stood out during my cyber browsing. Upon further research, I discovered that Kees Moerbeek was involved in the production of all of these titles. Not all of her books have increased in value the way these have. Are there any indicators or ways to predict which titles this will happen too, or which ones I should add to my collection NOW?