I think the development as far as what you have built is great. The area of need is getting the prices right.
It looks like you are doing almost all you can to maximise your chances for attendance (winning away games (except the last one) winning TV matches) but you did lose to your Rival.
Since you currently have 7000 Bleachers and at most have only sold 6190 (88%) at $9 and are adding another 1000, I think $9 is too much for you to sustain, maybe $7-$8 (100% @ $7 = $56000 @ $8 = $64000) might work if you continue to win ( I would go with $8 personally). Other seats; Lower Tier to $30 ($27000), Courtside Seats to $90 ($27000) and Luxury Boxes to $600 ($6000), Total = $116000 @ $7 Bleachers or $124000 @ $8 Bleachers.
Either way you are going to have an Arena that is able to sustain the best roster in your Div when you feel you want to change direction and focus on promoting. I would say, start getting your Game Shapes and Enthusiasm into their peaks and make a run at promoting and continue your development in Div IV where you would get the promotion bonus to get you started and the attendance bump to make way more cash.