If you take TOLL 417 southbound you will encounter 5 mainline toll plazas costing $2.00, $.50, $.50, $1.00 and $1.00 for a total of $5.00 one way. This assumes you leave the 417 at Exit 6 (State Road 536) which leads directly into Disney and becomes the EPCOT Expressway. (EPCOT Center Drive) If you remain on the 417 to Exit 3 (Osceola Parkway), there will be an additional ramp toll there of $.50.
As noted, much cheaper is to use I-4 since it is free. But it can also be gridlocked so only use this option if you leave the airport after 9am and before 3pm (or after 7pm). Leaving the airport, take the 417 northbound (1 toll, $.50) to I-4 and then I-4 to Orlando and Disney World.
BobK/Orlando