I was going to say Lolita, but then Humbert Humbert’s whole M.O. is to be able to provide for Dolores so as to possess her. To accumulate material wealth (house, inheritance) of which she is just the final object. So I guess it’s the same as Cinderella, who for doing the same thing to Prince Charming is the Humbert Humbert of that story, just as Lolita is the Cinderella of hers, even if she is not getting the same kind of emotional benefit from the arrangement.
Maybe…Dr. Zhivago? Zhivago just wants to be reunited w Lara. (Although since both Lara and Yuri start wealthy and end poor, it could be argued that their love could be an attempt to rebuild their fortunes.)
It might also have to be with how we define love stories. The Grapes of Wrath is about people having shitty lives, even though Ma & Pa Joad and Granma & Grampa Joad love each one another fiercely. Would we call it a love story if the book wasn’t about them losing everything? Or rather, can we call it a love story despite them losing everything? (Or alternately, to get a classic love story just run the book in reverse. The Joads get their money back, Connie & Rose of Sharon get back together, Grandma & Grandpa come back from the dead, and it all ends with a big reunion on the family farm)