So here is the problem with T20. In football leagues the Pro game and the game you play for country is the same - same skills. Top players play for their countries and make money as Pros. In T20 the skills are different from Test cricket. Test cricket is more "important" but there's big money in T20. So what will kids work on - Test or T20 skills? That's the real challenge - that the Pro game (T20) and the game you play for your country have different skills. If you are a good Test/50-50 player you may not make the cut in T20 (see Dravid, Laxman, Jaffar) - so what about them - they make less money than a Virat?
Maybe a system needs to be put in place so that top Test cricketers get management deals (as coach, etc) - coaches in Pro leagues can make tonnes of money too. Then you get rewarded for being a Test player. Or you need to find a way to boost BCCI's annual contract to make it on par with IPL deals. Or maybe there can be clauses on promotion - i.e. if you play IPL you can promote only your team (no other brand). If you play for country too you can promote IPL and other brands - that will offset any IPL vs BCCI contract salary difference.