Any combo tickets for Museums in Florence?

Alice,

The 'Firenze card' has it's benefits but it depends on what else you want to see( besides what you listed above)
& how long you will be in Florence. The card is good for 72 hours but you can only visit each museum once.

Here is a good article that will help you decide. http://www.visitflorence.com/florence-museums/is-firenze-card-worth-it.html

If you are only interested in those sites, it may be better to pay as you go. Don't short-change the Accademia, there are several other Michelangelo sculptures on your way to the David, and the galleries upstairs have some very good medieval/renaissance religious painting (small museum, won't add much time for a brief visit upstairs). Another place that is interesting is the small museum of San Marco, on the same street as the Accademia. It was a Dominican convent and each room (cell) upstairs has a fresco by Fra Angelico, as well as some beautiful paintings on the ground floor. I think the cost is 4-5 euro.

I experienced no line to buy the Santa Maria Novella ticket (no combo offer there other than the Florence Card) and also wouldn't expect much line for the Medici Chapels (one of my favorite sights). People typically reserve ahead for the Accademia and Uffizzi in order to avoid ticket purchase lines and capacity-control issues.

Ditto Laura's post: we didn't experience much for lines at all at the Medici Chapels or S.M. Novella. Pre-purchase tickets for the Accademia.