Pow's shallow hypothesis on beauty: Most beautiful girls are rich. The poor beautiful girls can use their beauty to find rich folks to get married. Of course, there are a few true loves over money. The beautiful girl usually gives birth to a beautiful baby via good genes.
Proof: Just go to any Dollar Store.
Second Proof: Give me any girl of average look. Koreans can transform her into a beautiful girl (even the height by extending the bones). However, the standard of beauty in the west and the east is different so specify your requirements.