Many of the toll booths are now transponder or toll by plate, no cash. A stick on transponder is $5 and are for sale all over in FL. If you can pick one up, go online to register and put some cash on it, that's the way to. If not, toll by plate is the only other option.
I-75 will take you down the other side of the state and add to the miles. When you get near Ft Lauderdale and Miami, however you get there, the toll roads are your best bet. Unless of course you like sitting in traffic with a bunch of crazy drivers that learned to drive in another country.
Just my .02. Go to sunpass.com. They have a toll calculator, you put in your starting and ending points, number of axles and it will tell you what the total cost is. If toll by plate you'll have to add the that cost. Don't recall what it is , check the sunpass site.