They could have made money on tags. Just clearly define the area, make the season separate from other big game seasons and tell the ranchers near the boundaries to paint orange stripes or something on their cows.
The National Park Service and CA DFG did that for a while on Santa Cruz Island, where the feral pig population got out of control. The island used to be privately owned, and NPS pulled the eminent domain thing, gave the owners pennies on the dollar, and kicked them out.
The previous owners were cattle ranchers who also held hunts on the island. Once NPS took over, the pig population exploded and for a while they let hunters pull tags for the island. Apparently pigs weren't dying fast enough, so they hired professional hunters from Australia to come in and night hunt them with thermals from a helo to wipe out the population.