I would also agree that the promotion hype dies down a little bit more after interdisional play, because that is what happened to me. The season after I promoted I raised my prices prices because my division was easier and because the playoff games, but doing so sacrificed a good chunk of attendance. I know this is after the time you can change your prices for interdivisonal play, but I think the prices you set are very good. I might have kept your Lower tier at 36, because you only had two games since you built the seats.You didn't sell out in your Private league game (which means nothing, I know, but it can help you with seat pricing and attendance) but then you did sell out in your League game agains the Wolves, who are second in your division. Against a lousier team I would say that you would not sell out, but you will still stay around 900-1000. Not sure how much difference two dollars will make the attendee's mind, but overall your pricing is very good.
I love your arena. Other than the bleachers, which I am assuming you are about to build more since you are selling out and didn't raise the prices, it is exactly the same.