Think about it. What other choice did he have? If he didn't give them enough, they would have killed him on the spot. I doubt a few survival provisions in his backpack would suffice. And even if he had given them a mountain of gold, they might kill him anyway to keep him from reporting them to the authorities.
They don't know his name nor where to find him, so they lost their only chance. And even if they did keep him, sooner or later the Depuri King will hear about his whereabouts and send his army there to retrieve him.
We're not talking about the perfect hero character. We're talking about a shut-in gamer with a very useful set of skills that he's still learning about.