All,
I just calculated incomes and profits for Arena improvement for arenas worth 1M, 2M & 4. Please note that I consider profit as income which is higher than what we have already paid for new Arena - ex. 1 000 500 income having 1M Arena means that our profit is 500$. Second thing is that I consider worst case scenario income per week raise.
Results:
a) 4M Arena - first profit is after 182 weeks (3,5 years)
b) 2M Arena - after 182 weeks of having this one,our profit is 730 000$
c) 1M Arena - after 182 weeks of having this one, our profit is 1 184 000$
I. after another 104 weeks our 4M Arena will have more or less equal profit as 2M Arena
II. after another 14 weeks (118) our 4M Arena will have more or less equal profit as 1M Arena.
After Total 300 weeks our Arena profit will be 2,6M$; 2,5M$ and 2,6M$ respectively. If we can have any conclusion, in my opinion Arena for 1M is the most reasonable one, first profit is after 83-84 weeks. You don't need to spend 6 years and then finally could say: ooh, it was good choice to spent 4M$ for this Arena, now my profit will be finally higher than one I would have if I had 1M$ worth Arena. 2M$ is not reasonable in my opinion. But anyone can have their own conclusions.
I hope this is fairly clear, you can add this information to general info about buildings/arenas improvements.
King Crimson