now this is my personal view, and other might not agree, but if you do not have your team for too long you probably are finding out where you can use money, and how high your expenses can be.
You probably do not have too many spectators at games yet, so your income will not be overwhelming. Therefor...
I would stick to the level 7 at the moment if I where you.
firing him will cost you an extra weekwage whcih he demands for leaving the club. A level 8 is a little better, but it shouldn't be the big diffrence worth your money at this stage in the game. The money will be better spend on something else, like scouting if you are not in the top of your division, or building some extra seats. a few luxury boxes cost a lot of money, but chances are you can sell them out if you only have 1 or 2...
They are not your friends; they dispise you. I am the only one you can count on. Trust me.