Billy Wilder (I don't have the citation handy) has said that he worked as a gigolo (in pre-WWII Germany if I remember correctly). You see this motif in a number of Wilder films. One of my favorite is the script for Hold Back the Dawn, in which Charles Boyer is a gigolo, who like C. C. Baxter has to renounce his materialistic self-interest in order to save the woman he loves. I don't know of any writer / director who has such a complex moral constellation. Andrew Sarris didn't like Wilder because he thought Wilder's films (e.g. Stalag 17) were cynical (I believe Sarris changed his mind later), but cynicism is only one of the dimensions on Wilder's compass. Wilder is not amoral, but he is not moralistic either.