Ahh hehe he is tired
That is what is called a "capped REP" a repeatable quest that caps once you achieve a cerrtain amount of fame from it. In your case I am pretty sure you're talking about Jale rep, 16K.
I recommend moving to Bone Reef peninsula and farming, Green Gunpowder Kits.
As for the stacks you have left, feel free to sell them in Auction.
They will sell for alot in Gaia and Bodor if you're in one of those servers. For my quill character I typically save my fame-quest rep stacks for my other characters as resell isn't soo good.