The  FIRENZE CARD is a pass which can be purchased on line, or directly in Florence ( At the ticket Office of the Palazzo della Signoria, at the Information point of the Duomo c/° Museo del Bigallo, or at the Information point of Santa Maria Novella in front of the main train station of Florence. Since June 1st the card will cost 85,00 euros for 72 hours. The card gives the opportunity of entering the main museums, churches, villas and gardens of Florence without reserving ( with the exception of Brunelleschi's Dome). During the 1st Sunday of the month, when States museums are free and cannot be reserved, the card gives you a priority to enter.

If you are an art extimator, purchase it! 
Reserve a private tour with your art major and official guide of Florence and visit the city with her!