More gold is created every day just by people playing the game and there's not enough gold leaving the economy with gold sinks. (That's why you see items in the Billions, since gold is losing so much value)
Lets be realistic though, you do know all those account roll backs that duplicated potentially 128 teeming necklaces, also just as easily could of doubled someones gold 7 times. So quick math... 1 billion gold x 2 x 2 x 2 x 2 x 2 x 2 x 2 = 128 Billion GOLD.
Oh and guess what.... Even though they changed the policies, to make items account bound on rollbacks, it doesnt apply to gold. So they (the bad people) are still doubling insane amount of gold at will. the money is not in the botting people.
Just saying. (probably worth deleting this post. lol)
EDIT... I got last say... HAHA!!
Anyway, for everyone here saying they would never resort to Third party options to at least sell an item, I bet most of you would change your tune if you found an item of extreme Hi-caliber. For example:
That has a current offer of 22 billion and a 30 billion buy it now price... If you did turn around and sell in the GAH, you might as well open your wallet and give your money away...