You are thinking in reverse, think it more like a kickstarter, you sponsor the author, at that point the author would probably just release as public domain and

You are thinking in reverse, think it more like a kickstarter, you sponsor the author, at that point the author would probably just release as public domain and you could buy a physical "official" copy on kindle or whatever, but you think it as just a tip/convenience or a merchandise, not the product.