Saw this on a forum, its not exploiting, its about buying herbs cheap as you can, mass making inks, and making BOp shoulders and vendoring them, to use gold to buy more herbs to keep milling for starlight ink to make mass cards. This works more if your a multiboxer or have a bunch of scribes, was used in earlu launch of MOP but if your realm still sells the cards, here is an easier way or possibly free way to make DMC's
TL;DR: Buy cheap herbs. Craft BoP shoulder enchants. Vendor them all.
I just got 1575 gold and 229 Starlight Inks for free with some milling.
I had 3000g on each 4 scribe (12000g in total), and I spent that gold for cheap MoP herbs (max. 1g60s a stack)
Milled all those herbs, and used all the Inks of Dream for crafting 724x Secret Crane Wing Inscription, which vendor price is huge 18g 75s.
So I had 12000g to spend, and after vendoring I got 13575g and 229 Starlight Inks in my bags.
If you are mass-producing Darkmoon cards like I am, then you're going to simply love this, but only if you can obtain herbs for cheap price.
I'm crafting 13 cards daily with no cost, actually earning a bit while doing this thing.