Very pricey indeed. Dick, I am so greatful I was in Italy before all the reservations had to be made, tickets had to be purchased etc. Quite frankly it makes me sad. Now when I go to Italy I don't have to worry about all the "have to see places". Been there, done that. But I feel so bad for the younger families or first time travellers that obviously have to time everything and spend so much money to see the sites and treasures.

My two cents: Skip Pisa. Spend the whole day in Florence. If you only have the one day and you're not a big art lover, maybe pick Accademia or the Uffizi. Agree with the poster who recommended Santa Croce. Another place I like a lot is the monastery of San Marco, where you can soak in great art (Fra Angelico) on a smaller, calmer, less touristed scale than the Uffizi.
Oh whoops, I see you're going in Sept. Advice may be too late ! ;-)