I would say get it. The story is short but even after the game there is so much stuff to do. You could try to own every building in every town and that could take some time. Or you could do the jobs and they're pretty fun... well some of them anyways. With Live, you don't really do much with the other people, all you do is hear them talk and say "I need this". But all in all, Fable 2 is a pretty fun game so I would say go ahead and get it.
"Humankind never forgives true greatness."