Apart when tanking, you don't make much money at higher levels. All the competitive leagues anywhere in the world have teams just scratching the red zone when they are willing to win and the one just below making some money, but not a lot.
You cannot create a system where the tankers lose money when tanking?
I am sure it has been suggested but why isnt there a limit to stadium expansion at each level?
Here is a thought.
Make 2 more teams able to promote/relegate from each league so there is more movement each up and down. Add a big bonus to promoting teams.
Put a seats limit to each division (this is example not real)
DIV 5000 seats
DIII 8500 seats
DII 11500 seats
DI Unlimited
If I am in D.IV, I can expand my stadium above and beyond 5000 seats but at the season reset I will lose any of those seats and I will go back to 5000 IF I stay in DIV. If I promote I can keep the seats. So I have to evaluate my season goals and expand accordingly. If at the end of the season I am in debt I relegate to the lower division.
Any time I tank I lose stadium seats, essentially impeding from making lots of money in lower divisions and forcing me to rebuild.