User blog comment:Martialmaniac/Why the Hunters Association?/@comment-10528819-20151205110311/@comment-5780397-20151205124747

Actually, the reason is that Gon had already spent all his money and pawned his licence. They earned money after completing Greed Island because Mr. Battera offered it, the Association wouldn't have paid for it. It is probably diferent for Temp Hunters, while Contract and Blacklist Hunters, aside from their normal assets, are also paid by their client (basically Killua and Gon worked like Contract Hunters in Greed Island) or receive the money of the bounty. But for missions that have been assigned directly by the Hunters Association, like the extermination of the Chimera Ants, yes, they would be paid by the association.

Yup, that is why I said it also depends on the chairman.