Whedon dollars weren't exactly super-bankable before the Avengers, either. I mean, Buffy and Angel had successful runs on fledgling second-tier networks, but Firefly, Serenity, Dollhouse, the original Buffy movie, he was not what anyone in Hollywood would have considered a sure-fire bankable talent, and while fanboys and fangirls rejoiced at the announcement that he would direct The Avengers, that doesn't mean it wasn't a risky bet for Marvel/Disney (did Disney own Marvel when that decision was finalized?).