Grand Master Hwang is no longer affiliated with any of the ITF groups that originated after Gen. Choi's death. He heads his own organization, Unified-ITF, which is supposed to work to bring the other groups together.
Anyway, the current costs for a iii dan in the ITF under GM Choi, Jung Hwa (Gen Choi's son) is considerably less that what you've quoted above and the price itself includes cuts for the instructor and national organization. That being said, it's common for some instructors to add on a fee to cover costs of a new belt, new dobok, having a guest examiner in, etc.
Pax,
Chris