I really agree with a lot of what McFatties said here but I am going to take it a step further.
There really is no over expansion. Unless you are talking 30k seating there isn't one. If I could do it all over again I would shoot for an arena with 13k bleachers, 7k lower tier 500 court side and 50 luxury boxes.
Keep in mind, it gets a lot harder to designate revenue towards arena the higher in division you go. If I could do it again I would do all of my arena while in D4 or D5, grab a couple of great trainees and build the hell out of them.
I saw the argument of 20 luxury boxes for 400 vs 10 at 800. I will tell you first hand that it doesn't work that way. Lower prices allow people that wouldn't normally be able to buy a 800 dollar luxury box buy a 400 dollar luxury box. So if 10 people are willing to pay 800 bucks for a luxury box then 23 or 24 maybe willing to pay 400. Sounds like minuscule gains but when you are setting a budget at the D2 or D3 level, it makes a big difference.
I have a pretty nice arena and it is a weapon against finances in my opinion. I demoted to D3 to do it but I now have an advantage over 99% of D3 teams once I get past the demotion penalty.