I was certain that at one point, there was intentional fraud along the lines of the old "change scam" where the person asks to change a twenty, then changes his mind about how the change should be split and gives one of the tens in exchange for ten ones, then says, "Forget it", gives that back and asks for the original twenty back, having already pocketed one ten. Monsieur Lheureux (and, as it later turns out, the notary) were probably used to running that sort of scheme.

I can see the book being turned into a socialist metaphor with relative ease as a result. Emma, the everyman, is seduced by false promises that society makes about wealth and happiness and becomes a slave to the banking and merchant class (Lheureux and the notary) and is used by the ruling classes (Rodolphe and Léon), and the peasants around her who might have sympathized with her plight and organized to help her are kept down with ignorance and festivals, while the urban proletariat is alienated from the land and its beauty.