For the 15 minute option, presumably they wouldn't charge anyone with a ticket for the original game and income from hospitality etc would be zero but they would still need to pay stewards and police.
If it's a full replay, Rovers can refund 40% of the original ticket price and then charge full price again for the replay, sell hospitality tickets and get income from food and drinks.
Pasha will be looking at this from a financial point of view and may well prefer the full replay