Two solid days of Rugby League and a Rugby Union international won't have done it too much good either. All of the events hosted at the stadium will have paid the club a significant fee for the use of the stadium, and I'm sure that will cover the cost of replacing the pitch, and some.
If you take into account the amount of food and beverages served, along with the gate receipts for these events, then it probably amounts to quite a pretty penny. Of course the food and beverage receipts will primarily line the pockets of the club's catering partner, Aramark, but there will also be a healthy cut of that going into the coffers of the club too.
They wouldn't be randomly renting out the stadium if there was no profit in it.