I much prefer driving out of MXP, but it is sort of a shame if you won't need the car once you arrive at your lodgings. You say that the others in your party have transportation arranged; may I ask what it is? If it is one vehicle for a large party, you may want the car.

How far outside of Arezzo? If you take the train, as you already stated, you will have to get to the train station in Milan, get the train to Florence, transfer to Arezzo, and then get from Arezzo train station to your meeting place. How will you do that? Taxi? Is it far? Will some one pick you up? That may be another factor in the cost.

It's about a 20 minute taxi ride from Arezzo train station. We're just meeting another couple there, so their mid-size rental should be fine. I was set to take the train until I learned the shuttle from MXP to Milan Centrale could take an hour.

I still like the car... where have you looked for rates? Did you try Nova?

I was just thinking that sometimes my biggest splurge on a trip is transportation. For instance, in March we will fly from Venice to Rome on our last day to connect to a flight out of Rome around noon. This will be expensive, but we will have the entire last day of our trip to enjoy Venice.

The options would be to spend the last night near the airport in Venice and save the early morning taxi fare to the airport (ugh), or to train to Rome the night before and lose our last evening (ugh, ugh).

So, the expensive water taxi early in the morning to the airport and the flight to Rome are the best way to maximize our all to brief trip to Italy. I am thinking that the case is similar for your trip from MXP to Arezzo.