I don't know for sure what conditions Inzaghi put forward to Inter Milan, but if the condition is a salary increase as offered by Al Hilal, then Inzaghi needs to prove his ability by presenting the Champions League trophy this season.
The rumor is related to a salary increase, but even though it will not be as big as what Al Hilal offered, I am sure Inter will give him a salary increase, especially if they win the Champions League trophy.
Another rumor, another condition requested related to bringing in several players that Inzaghi wants. If the financial situation and competition in the transfer market are good enough, it should not be a problem to attract good players to come to Inter.