So far about 20 gold has been spent on drinks at the tournament. Assuming it reaches 50%, and you have a 20% tax share, that means you'd get about 10 gold. I find that hardly worth a dev's time.
I was thinking along the lines of 2 gold every time the option is used. Seems to me like this would be a simple code to implement, much simpler than gambling would be.
But no, I don't expect this to make tournaments any more profitable.
