Google is showing AuthorShelf for AuthorStream pricing because the names sit next to each other. They are not the same company.
AuthorStream
AuthorStream has historically been a site for hosting and sharing presentations/slideshows (authors sometimes used it for talks). Pricing, if any, is on their site — confirm there. It is not a book production package.
AuthorShelf
AuthorShelf Inc. (Maryville, TN) sells listed self publishing packages from $399–$2,989 and author services (editing, cover design, formatting). Lifetime portal. 100% rights and net royalties. No monthly portal fee.
Also confused with
AuthorScale is a social-content marketing app (~$20–$50/month). Different again. If you meant publishing packages, start at packages. If you meant a slideshow host or a TikTok scheduler, you want those other products.