To be honest, I would raise salary floor to TV incomes + 50% of ticket income. This is stupid that a tanking team can pay only as much as TV incomes and save 150-250k a week
plus getting a good draftee. This bigger slary floor would make teams build bigger stadiums as well: bigger stadiums -> bigger incomes -> bigger amount stays in your pocket even if you are tanking (and of course bigger amount is going away as well). So tanking teams should spend more (to stadium) to save more which would make tanking almost meaningless (in financial way, of course the good draftee is still there which is a good thing).
After that, your solution is acceptable for me
Until then it just helps tanking in my opinion.