Maximizing output from minimal input
gs2, 412 + 5.37 * 10902 + 1010903.1 bytes


f pushes 1\n2\nFizz\n4\nBuzz\n...\nFizzBuzz as a 412-byte string.
fô prints all of its permutations, so 412! * 412 characters.
fôô prints all permutations of that 412!-element list, where each element is 412 characters long, so 412 * (412!)! bytes.


EDIT: To put things into perspective, this is at least 


  101000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000


bytes, dwarfing all of the other answers here so far.