Under the term of service of 2.2 which states the following.

2.2 Real Money Trading, Farming and Power-Leveling. You may not sell, purchase or exchange for real-world money or value any in-game currency, accounts, characters, in-game services, or in-game virtual items. You may not play the Game for the purpose of acquiring virtual items or advancement in game play on behalf of a third-party or for the purpose of selling any virtual assets to a third party for real-world money, specifically including "gold-farming" and power-leveling services.

Selling runs is activity of power leveling for in game currency. Which promotes RMT purchases. On an average cost of 500,000 gils. Something need to happen to stop guilds from doing this. It clearly states no selling of any virtual services and advancement in game which this is consider of type of behavior.

Personally I would make example of guild leader, but anyone in the guild taking part of should be all ban few days first warning and escalate upward for repeat offenders.