This is a topic that I recently brought up in IRC with some of my fellow Wind Trader from The Consortium forums. A few of those guys have blogs listed on my blogroll, so if you're interested, you should be able to check em out either place.
At any rate, I've been a bit concerned lately about recommending making 522 gear to folks who ask me for goldmaking tips. And part of the reason is that I remember what happened with Blood Spirits. In case you forgot, let's have a look at the data provided by The Undermine Journal - for all realms in both the US and EU:
As you can see above, it took awhile for Blood spirits to drop to prices accessible by mere mortals. But, by January of this year, they stabilized around 2500g. What happens next is subtle, partially because of the scale of the graph above. Fortunately, TUJ allows us some flexibility as far as zooming in goes:
Again, as you can see above, Blood Spirits fell in price - and believe it or not, they fell rather sharply. While they had been approaching a steady stat of ~2,000g, they've now approached a steady state of ~200g. That's a ten-fold decrease.
This wasn't caused by a sharp decline in demand, though. Rather, it was caused by a jump in supply. You'll notice the big drop started in March at the same time that patch 5.2 launched. That's no coincidence. Patch 5.2 began adding Blood Spirits to the "Fail Bags" in LFR. In addition, I believe this is when they were also added on to the Valor Vendors.
If Blizzard is anything, they are, at least within expansions, a creature of habit. At 200g a shot, it's pretty straightforward to mass produce 496 gear. And to be certain, there is a definite market on a lot of servers for a couple reasons: first, they're not the best you can make (even though the 496 craftables are on different equipment slots from the 522 craftables), and second, because folks don't like to touch markets they think are in decline or crashing. The crash in the month that followed the introduction of patch 5.2 in the price of Blood Spirits surely screwed anyone who had stockpiled them prior to the patch and was not able to offload them quickly. In fact - it probably dissuaded those folks who did lose their shirt from staying in the market.
But that's old news, isn't it? Well, we really want to apply some of this hindsight to what might happen with haunting spirit and the craftable 522 gear. Let's have a look at these:
Of course, these weren't added to the game until 5.2 went live in March. It's hard to see exactly where they've settled over the last couple months unless we zoom in:
Which is still a bit hard to read unless you've it in front of you in your browser. The short of it is that we're at about 4k per haunting spirit. That seems to leave a lot of potential for a ten-fold crash in price over a month after the introduction of patch 5.4, if Blizzard decided to treat Haunting Spirits similar to how they treated Blood Spirits.
Of course, that might not happen - Blizzard may do something entirely different. They've a history of being a bit coo-coo with these sorts of things, and their 'design intent' is about as ephemeral as the ghost of Blackbeard himself. But given the current information we have, it doesn't seem like the best idea to stock up on 4k gold Haunting Spirits (or even 2k gold ones, for that matter), in anticipation of the patch.
A better idea would be to wait til these start to crash, and get in on them in sort of a "just-in-time manufacturing" sort of basis. Even with prices in free-fall, you can offload a small inventory a lot easier than you can offload a stockpile. And the guys who did stockpile will be dumping, but you can bet that once they clear out their stock, they're cashing their chips out and going home - leaving the market all to you.
So keep an eye on it. Markets aren't 'good' or 'bad' - they're only stable or changing. And so long as you know which is which and use your brain, you can make gold off either one. What markets do you think will change in the coming patch? Have you looked at the data to try to validate your ideas?