Rupel normally goes after something precious from the person who wanted to make the deal hence why he wanted Cinderella’s baby. The most precious thing to Maurice was Belle. Even Belle asked him why he wanted her and he replied “The place was filthy”, but she guessed that he was lonely and I don’t think he denied it. I love it when he talks about having a caretaker for his “rather large estate” because it just sounds like one massive euphemism.