Ok, so... about $8 million revenue, -4 million in expenses... that's still $4 million that your team will be making in a single game!
Don't forget the insurance in case the game couldn't be played and the tickets needed to be refunded ($400k).
Added player insurance in case of injuries, as this game wouldn't be covered under the normal league policy (cost determined per player).
There are all kinds of other costs.
The Oilers made about $2 million profit after everything is added up. I am sure if they held the same event in skyreach (with the Alumni game), and an increase in ticket price, they could have made close to that much.