Can anyone tell me which site is the cheapest to book museum tickets. I need to go to uffizzi, pitti, accademia and battistero and palazzio vecchio.. All sites have different prices. We are to be family of 5 three children under 25
I would suggest you just book Uffizi and Accademia -- the cheapest way is to call and book that way +39-055-294-883.
If you have kids under 18, they get free tickets, you only pay the prebooking fee of 4 euros for these two museums.
Online, we recommend you book on http://www.uffizi.org through our partner Florence-Tickets -- because you CAN change ticket dates or times if you were to need that. Online you par prebooking and online commissions.
Pitti, Palazzo Vecchio and Baptistery - just buy tickets on site. The ticket offices here normally don't have long lines.
The Baptistery is a pass which will also include the climb up the duomo, the belltower and Opera del Duomo museum too.