Vellum

Vellum does one thing: it turns a finished manuscript into ebook and print files that look like a publisher made them, with chapter headings, drop caps and ornaments that are already correct rather than waiting to be designed. Authors buy it the week they realise their own formatting looks amateur next to what is on the shelf. It runs on macOS only, which is a genuine barrier and the single most common reason people end up elsewhere.

Vellum Ebooks is $199.99 and Vellum Press is $249.99, both one-time purchases covering unlimited books rather than a per-title fee. The fifty dollar difference is paperback output, and the version without it cannot produce print files at all. There is no subscription and no separate pricing page, so these figures come from the homepage. The cost is front-loaded and does not recur, which is what makes it defensible for somebody with a series planned and hard to justify for one book.

An independent author on a Mac who has finished writing and now has to make the book look like a publisher produced it. It suits somebody publishing more than once, because the price only makes sense amortised across several titles. Anybody on Windows is simply excluded, and that is the most common reason people end up formatting elsewhere.