What quotes from Romeo and Juliet show that the feud was caused in regards to a competition for social status and wealth between the Montages and Capulets.

I think we might trace tclues from the prologue. We see the first clue in the Prologue, which opens describing the families with the line, "Two households, both alike in dignity." In this context, the word "dignity" can be translated to refer to "elevated rank, office," or "station" . Then it goes on to say, "From ancient grudge break to new mutiny." This suggests that this fight is over social status.