I can see that the previous posts focused on post-war American films with male leading characters. You might want to look at films from other national cinemas and different eras such as:
-Strike (1925) and Battleship Potemkin (1925) by S. Eisenstein: they contrast individualism and collectivism. In particular, Strike portrays the oppresive forces of economic materialism through visual metaphors (animal slaughter, lemon squeezers) that are interwoven in the narrative through an editing completely different from Hollywood.
-the Italian neorealist films Yesterday, Today and Tomorrow (1963), Marriage, Italian style (1964) both directed by De Sica and starring Sophia Loren and Marcello Mastroianni. The former is an anthology of three episodes where the themes of love (and sex), gender and materialism are closely connected. The episodes contrast the materialism of the upper classes with the ways the disinherited are forced to adopt to survive. episode one (Adelina) shows the connection between motherhood and materialism as Adelina is forced to give birth to babies to avoid jail. In episode two, snobbish Anna remains indifferent when she almost runs over a child while on her husband's Rolls Royce with her lover. In episode three, the prostitute Mara has to cope with the materialistic demands of her clients and her spirituality. Marriage, Italian Style links the sacred institution of marriage to materialism and economic stability. Filomena who has been the mistress of a rich businessman for decades decides it is high time he married her and supported the entire family;
-on the relationship between sex, gender and materialism also check the Visconti episode in Boccaccio 70, where Romy Schneider decides to become a prostitute;
- Bycicle Thieves (1948) again by De Sica, following a man's desperate search for his stolen bike through the streets of Rome. The bike is essential for his job. It could be interesting to see how The Icicle Thieves (1989, Ladri di saponette) pays homage to De Sica's film by showing how the corrupting power of advertising and materialism brings the characters of De Sica's film in a consumerist heaven (or hell?).
- Human Resources by L. Cantet (1999) showing how an idealist trainee manager has to come to terms with the materialism of economic production;
- Los Lunes al Sol by Ferndando De Aranoa (2002) following the crises of middle-aged Spanish unemployed;
- Rosalie Goes Shopping by Percy Adlon starring Marianne Sagebrecht of Bagdad Café as a German bride who learns to use credit cards without having any money;
- Le couperet (The Ax, 2005) by Costa Gavras: a dark satire of downsizing and outsourcing where a fired executive becomes a serial killer. Why not looking at this together with American Psycho?