Sorry for the confusion. Im kind of learning this all myself too. This link should take you there, live now: https://www.backerkit.com/c/projects/straycouches-press/crawl-collectors-edition...
The aether edition is just the PDF. Which you should be able to download from here for free (don't have to pay anything). The new Mega-Edition is print only, and will not have any real new content.