I believe the cost when we did the tour was 600 euros for the van for up to 8 people. That worked out to 75 euros per person which was a much better deal the all day Florence Pisa ship tour which was I think around $135 a person even with the exchange rate.
As I said in my earlier post Paola did an excellent job of telling us what we were going to be seeing on our trip from Livorno to Florence and then guiding us through the various sites as we explored them.
I will say that one day is definitely not enough time to actually see all of Florence let alone try to do as we did both Florence and Pisa. My wife and I have both decided in some future vacation to go to Italy and spend 4 or 5 days in northern Italy, Florence, Genoa, Pisa, etc and then spend another 4 or 5 days around Rome and central Italy and then finish with 4 or 5 days in southern Italy, Naples, Capri, Amalfi coast and a longer visit at Pompeii and Herculaneum. Now all we need to do is find the money to do it. But we probably won't try it until the euro to dollar exchange rate gets a little better than it is now.
Enjoy your cruise and I hope you find good private guides for all your ports. We did two ship tours and 4 private guides and enjoy both types but I definitely felt we got more for our money in the private guides over the ship tours.
Happy cruising.