Sanctioning Bodies Fees

So the fact that Golovkin is fighting Rubio and Rubio's WBC Interim title is up for grabs has just got me thinking. How much do fighters have to pay in sanctioning fees to the Governing bodies? Does anybody here have an inclination. I'd love to know Read the rules on their (WBC, WBA, WBO, IBF) websites, it tells you all that sort of information.

3% or an agreed upon flat fee because i doubt he sanctioning bodies get 3% in the bigger purse fights