In such high level, can a team be breakeven by reducing numbers of players and using more lower rating players? If high level team can be breakeven by using 3* players, in my opinion the game is still playable.
In this situation, league teams whose owners do not intend to inject cash through real life, will fight for signing 3* players (the lowest available in auction market), and re-sign their own low-wage 1*, 2* or 3*players. As the result, there will be more teams comprised of low rating players. The options of acquiring new players will be less. But this is still a fair game. The focuses of the managers will turn more to maintain the financial health of the team. This is another challenge.
However, in case even wages of 3* players are too high, then the teams will have no way to run.