I have known people that made their gil doing non-repeatable quests on a mule, sending the scrolls/items to their main's to sell, and then deleting the mules. It is not impossible to "farm" these, just a bit more trouble than most people want to go through-- Hence the price on most non-repeatable quests.
well the price of these will hit rock bottom, as everyone is being forced to complete the mission for the new trust npc Shantotto these will be worthless in no time
What needs to be done is make all of these quests available at a minimum of the level the job can use the item/spell. This would seriously slow down RMT activity. Sorry to the few non RMT that make their gil this way.
This item is currently being farmed somehow by RMT on Garuda server, being repeatedly sold by the same person several times a day.
This is an unrepeatable quest!