In the old days I would have gone for the fifty pages and waited the year, but now I'm not so sure. If you can't sell them in ten pages, you probably can't sell them in 50. Of course, that could depend on the story, too, but who's to say they will read all 50 pages just because they let you mail them that many?
Anyway, this is good news for folks who want to try to get published the semi-old-fashioned way. The electronic transom is now open at least a few inches.
Or did everyone else know this but me?