Great life? What is a great life? Is it having a great amount of money, two children and a wife, but still being in a mid-life crisis? I think Billy Pilgrim and Cinderella are different, in some ways. She could be a metaphor for what happens to Billy, but not the perfect one.
This is what Gabriela Aldana said in her blog entry "Billy Pilgrim Was Cinderella, and Cinderella Was Billy Pilgrim." She said that Billy goes to war, which could be the time that Cinderella had to work with her stepsisters and stepmother. Then, she gets married to the prince and lives a happy life, for ever, until she dies. In Billy Pilgrim's life this would be the part where he gets married to Valencia, she's rich, he becomes wealthy and "lives happily ever after." Does he? Does even Cinderella live happy ever after?
We assume that Cinderella lives a fully satisfactory life, since it is a fairy tale. But, are you sure that every single day of her life she was completely happy just because she is away from her step-family and she is a princess? You never are. Maybe, she never is happy (all the time, there are moments you can be happy now).
I think it is the same with Billy, maybe in that way they would be similar. (Still, I think they are not similar). Billy went to war, Vonnegut has explained how war is, it's horrible. Then he married a horrible woman (inside and out) and then he "lived happily ever after," with a bitter wife, and an intolerant daughter. Oh and I forgot to mention that he somehow hates Valencia, he just didn't tell her. He didn't tell her anything. Not even his Tralfamadorian thing. Such a happy life. Honestly, I wish I had a family to which I couldn't tell them anything because I would be called freak! It would be amazing, having a completely socially awkward family and be stuck there...'TILL YOU DIE.