How much would a trip to Italy cost? (Read Details)?

I would wanna know how much the airline tickets would be for 2 people (from las Vegas to Italy and back) how much dining out would be, and to tour a lot of Europe(countries like Italy, Germany, France, and Switzerland) also I would like to gi everywhere in Italy from Sicily to Verona to Rome (I'm siciian so I have to see sicily) I would like to know all that because I would like to know how much a trip there would cost. Oh ya AND ALSO how much lodging would be in France and Germany? The lodging in Italy will be fine cause we have family there.