That does seem high. We did a 2 week road trip around Italy, started in Milan, then Venice, Florence, Rome, Pisa, up to Turin & back home through Switzerland. Granted we are stationed in Germany & we didn’t have to pay for flights, for a 16 day trip we paid less than $3000, gas, tolls (there are so many! ), rental car, a ton of delicious food & countless glasses of wine included. We didn’t skimp on anything. I’d assume once everything is over with the corona mess there will be a big push for tourism & everything will be even cheaper. I’d continue with your plan, but wouldn’t be surprised if you spend a whole lot less than you planned.