As you already know,if you want to upgrade clan buffs to level 3,you need gold bars. While adding them to shop could cause problems of people buying them and npcing for 10g each just to abuse the system,you can add them to an npc,let's say shady dealer for 10g each which is their npc price. We get to finish the quests and use the item when needed,and no one suffers.
Thanks.
Let's make crafting great again...
level 8 craft is way too much effort for a simple quest item.
They can also drop from Treasure Hinting Charm quest.