"There is one ameliorating factor, however. When the IPL began signing players who were on central contracts with Cricket Australia, the governing body got 10 per cent of the IPL deal. This still happens, but CA has just gone a bit quiet on the windfall.
It’s a great theory: money back to the system that has invested heavily in the production of the player, but will private owners continue to agree? No other T20 tournament pays this premium back to CA. Perhaps they should."
If I was CSA I'd be wanting a return on the investment they made in their system.