You could think about binding it to the next paid player if the aim is to have superstars dispersed more evenly.
If it helps, it could even have a fixed % over the average of top 2/3 players, as needed I suppose.
And yes - you probably should bring a bit more money into the game via the TV contract as well. But definitely you should also increase the salary floors (%) in all divisions. This will achieve two goals at the same time:
1) Will make tanking much less efficient. Competitive teams won't feel it at all.
2) Will virtually give a bit more money to teams in lower divisions (the salary floor is a percentage of TV money - the higher the league level, the bigger the %)
I think this is part of the "other" possible changes/means of extra revenue.
Not sure if the "team consolidation" won't do something there already, at least at the lower divisions.
Sounds promissing though I'm sure it's something that has to be tinkered with carefully in order to keep things "balanced", especially with such diversity between countries.