So, basically, last session, the person the players were escorting went back to his hometown, where he owes a massive debt to the residents. The residents of the town threatened to repossess his boat to pay for the debt, stranding them on the island where the town is. Long story short, they decided to go kill an ogre for money.
In the big ogre fight, the person the players were escorting ran off from the fight, so now they have a massive amount of money from the bounty. The original idea was that the money would be used to pay off the debt, and they would have a small amount left. Of course, this is a bit of a problem. I have a couple ideas. There already is a lot of crime in-game, so I could say it was stolen. There also is a financial crisis, so I could raise the prices of items to compensate. The second one might be a better idea, because the players haven't played much D&D before, so they wouldn't know the standard prices.