Here India wants to lead the world cricket and also they want to adopt some strategies that can help them unique. I think it's also a trick that they don't let any of their players play in any outside franchise. That's why they spend more money on the value of their players. But even if they permit that, franchise would have to pay their players more than others. Basically BCCI will not allow it in any way unless maximum profit is available for their players.
There is some justification behind this move, as the BCCI plays 20% of the player's fee in the IPL as "foreign player release fee" to the respective national cricket board.