Unfortunately, even in sports…the richest have advantages. They can afford the best gear and the best trainers and can afford time off to practice. However, what you want the game to be and what the game actually is can be two different things. Ultimately, the bosses just drop loot and its for the players to decide how to distribute it.
However, all of that is completely irrelevant to GDKP and gold buying/selling. By your own admission they can be run completely legitimate. Trying to stop something completely legitimate because someone MIGHT or CAN use ill-got gold in that system just doesn’t make sense…its like closing down a restaurant because someone might spend stolen money. You don’t do that…you punished the guy with stolen money, not the business.