Unfortunately you're too late. Sam was able to persuade Dean that betting on house mates fighting was inappropriate.

OK, don't tell Sam, but what really happened was Dean had to close the book because everyone but Quill and Drax bet on Tassie, and Dean didn't have enough money to cover the bets. Especially when Drogon put down a hoard of gold.

We're all a bit concerned about where Drogon got that . . .