I'm guessing (and others have speculated) that there's been a new rash of botting on many servers. Prices dropped to 50-55g per stack on my server last week. I snapped up dozens of stacks - about as much as I could fit on my main and my mules.
I'm pretty confident that Blizz will ban these accounts soon, which should lead to prices climbing back up, which should have a ripple effect on the enchants and metas. It may have already happened - right now the lowest price on my server is over 110g per stack.
The other crafters on my server have been selling aggressively at the low prices, so I'm betting that they'll run out of stock sooner than I will. I'll start leaking my stuff back onto the market if/when prices start climbing again...we'll see how it goes.