I know the numbers look gaudy, but I'm not sure this is really that unusual. I don't know what LSU ticket prices are like, but years ago I did work in Columbus, and was told by an IMG rep with Ohio State's AD that the average gate (at the time) for an Ohio State football game is about $8 million.
In this case, LSU's money is all cream, since they don't have to staff the arena or pay the power bill, but its probably not exorbitantly more than they make in profit from a home date. The losers here are their fans, who now have to travel to a home game and pay what is certain to be inflated ticket prices to see one of these "regular season bowl games" at a neutral site, against two teams that would be less enticing than anyone on their conference schedule, aside from maybe Kentucky or Vanderbilt.