In my lame opinion: "para" = for a purpose For what purpose is my money? 'Por que tengo dinero' = "why do I have money? = How did I get money?
Yes! I just looked this up. When asking questions, "¿Por qué?" means "Why?" (for what reason) while "¿Para qué?" means "Why?" (for what purpose). The wording here implies the speaker is seeking out a purpose for the money.
"¿Para qué yo tengo dinero?" answer wasn't accepted as correct Is it actually ok to use Yo in this phrase?