While quite expensive, my wife and I found the private trip to Lucca and Pisa was a good value. This was due, in good part, to our driver and highway guide who was knowledgeable, humourous, and unflappable--as proved during our 3-hour trip from Pisa back to Florence when a major accident on the main thoroughfare closed the road to traffic. We loved the four hours alone and without a guide in Lucca, the old part of which is small enough to navigate without a guide. Make sure to see Tintoretto's 'The Last Supper' at the Cathedral San Martino!!! It's superb! I recommend Buca di Sant'Antonio for lunch. It's just off the main piazza. Pisa was less interesting, but a worthwhile side trip. Because of the cost of the day trip, I was put off by having to pay for tickets to enter the baptistery, as well as the Museo delle Sinopie.