New York -> Las Vegas one way costs approx. $34k which includes: Aircraft One-Way Rate, Fuel Adjustment, Additional One-Way Fuel Adjustment, Flight Crew, Crew Layover, Crew Meals, Ldg/Hdlg/Ap-Fees, Use Tax, and Federal Excise Tax. Those line items are a copy/paste from a real invoice. I’m sure you can extrapolate what a private flight from US to Italy would cost.

Btw, when you fly private, I don’t think it’s courteous to split the tab...normally, one party handles it all.