In the beginning Marvel created the Bullpen and the Style. And the Bullpen was without form, and void; and darkness was upon the face of the Artists. And the Spirit of Marvel said, Let there be The Fantasic Four. And there was The Fantasic Four. And Marvel saw The Fantasic Four. And it was good.
I think a 23-page ordinary comic is an investment for the artist, but if you're doing something 60 to 104 pages, that's a really big investment for an artist. So unless you've got someone who wants to pay you while you're doing it or up front, it's kind hard to get someone to do that with you, unless you're the artist yourself.