If you decide to book the tickets online on B-Ticket or via call center there is an additional fee of reservation (either 3 or 4 euros depending on the selected museum), that grants priority of access at the date and time selected during the online purchase.
The fee is already included in all the available fares present online.
If you do not want to pay the additional cost you can buy the tickets directly at the museum, however without the priority of entry you will have to do the queue.
We remind you that in order to visit Michelangelo's Secret Room the reservation is mandatory, for this reason it is not possible to purchase the tickets onsite.