Chaos orbs are first here because they're a little weird. Right now, they're still BoP on the PTR, which means that people who decide to craft and sell the new gear will be limited by the number of heroics they're able to run. Of course it's just a formality -- on most realms, the vast majority of the time you can find someone with the orbs who will let you use them with your mats if you "tip" them. The average value of this "tip" is actually the price of the Chaos Orbs. This will be the best way of mass-producing the new craftables unless you happen to have a ton of them laying around. In any case, expect the "tip" (price) for these to skyrocket when everyone wants them 6 at a time to make new raiding gear. Don't waste these on 4.1 gear, and see if you can arrange something with people you see advertising in trade where you could buy their orbs in advance for the 4.2 craftables.
The new craftable BoE gear is going to come from jewelcrafting, engineering, inscription, blacksmithing, tailoring, and leatherworking. Like every content patch with a new higher maximum ilvl gear set, the BoE gear will be the first target on everyone's list to help them get access to better (and more) BoP gear by getting ahead on performance.
All of these recipes take volatiles and raw materials. You can safely buy volatile anything for what's considered a good price on your realm right now, and it will sell for considerably more when 4.2 hits and dries up absolutely all the stock.
Jewelcrafting is getting some nice PvP blues. These recipes are going to be trainable at the main cities, and worth noting is that these recipes require a skill of 510 to make. They will likely become a cheaper alternative for leveling jewelcrafting, so will only be profitable when the demand for low level PvP gear is heavier than the supply generated by jewelcrafters leveling. Even when this pushes the price under the cost for the mats, the levelers will continue to sell their goods because almost everything while leveling is a loss.
Engineering is getting the new hunter gun, and a critter launcher to attach to it. Every single hunter not currently using a heroic PvE weapon or a 2200 PvP weapon is going to want this weapon, and it takes Chaos Orbs, Truegold, and Hardened Elementium. Every hunter, whether they have a good 4.1 weapon or not, will want the woodchucker.
The schematics for this gun and "scope" are sold by Damek Bloombeard, and you have to unlock some quests or phasing to get access to them. This means that the first ones to hit the market will be sold for a vast premium over the value of the mats, but as more and more people hit this requirement, the price will reduce. As it does, however, more and more hunters still using ilvl359s will buy them, pushing the supply harder.
Inscription is getting a couple of PvP blue relics, also trainable at the trainer. They take inks and volatiles, so won't be much more than the mats assuming you have a healthy supply of auctioneering scribes on your realm. I might suggest stockpiling Inferno Ink, but scribes tend to have a surplus from their glyph business. Also, the demand for darkmoon trinkets (the current best ink sink) will not be very high in 4.2, so make sure you get rid of anything you've stocked before the supply catches up.
Blacksmithing is getting a huge list of craftables. The PvP blue gear is now ilvl358, but the recipes will already be in the books of anyone who currently knows the ilvl339 versions. For example, if you already paid 20 Elementium Bars for the Ornate Pyrium Belt recipe, you'll find it's changed to the Bloodthirsty Ornate Pyrium Belt with the same mats when you log into 4.2 for the first time. If, however, you have any of the old ilvl339 gear in your bags, they will remain ilvl339. Try to avoid getting stuck with these.
The ilvl365 weapons that everyone will want seem to take mostly Chaos Orbs, Truegold, and Hardened Elementium. There are also a few blue and green quality gems thrown in, and a whole lot of volatiles. The key here is that the plans are, again, only available from the Firelands hub. Their demand and price will follow a similar trajectory as the new hunter gun from engineering.
There are no craftable ilvl378 weapons, but there are a few pieces of armor. There's no way to tell for sure how people will get the recipes, but it's likely that you'll be able to buy them for Living Embers, and they may drop off bosses in Firelands. You'll likely need firelands rep as well, so these items will be almost as hard to make as their equivalent would be to earn in a raid. While, their materials lists are pretty hefty, they don't take Truegold, instead focusing on Volatile Fire and Hardened Elementium.
Tailoring is very similar to Blacksmithing, however you don't have any ilvl365 weapons. You do have a long awaited bonus, though: the Luxurious Silk Gem Bag. This will likely be a decent seller for the first few months at least, and will continue to sell as people level jewelcrafting. You get the pattern from Ayla Shadowstorm after doing some quests. The reagents are only three Dreamcloth, however as you can tell from the rest of the craftables, the value of Dreamcloth is about to skyrocket.
The ilvl378 BoE armor craftable by tailors take only Dreamcloth and Living Embers. The most important thing you need to know about tailoring is that you should be saving your dreamcloth now, and stockpiling volatiles to ensure that you can continue to make them in patch 4.2. You can also always make more with Chaos Orbs off the cooldown. Every single tailor trying to make these will be buying as many as 150 volatiles a week.
All the blue PvP gear that tailoring is getting in 4.2 will automatically update to the new ilvl with the same materials cost, the same way it's happening for blacksmiths. Don't get caught with old ilvl339 gear in your bags the night of the patch!
Leatherworking is getting two bags to tailoring's one: the Royal Scribe's Satchel and the Triple Reinforced Mining Bag. Again, the patterns for these are both bought from Ayla Shadowstorm. The mats for both bags are 3 Pristine Hides and either some Volatile Earth or Inferno Ink. As you possibly know, you can trade 10 Heavy Savage Leather in for Pristine Hides in your main city, so each of these bags is really made out of 30 Heavy Savage Leather.
The blue PvP gear is getting the same treatment as Blacksmithing and Tailoring, and is made with mostly Heavy Savage Leather, volatiles, and Blackened Dragonscale. All of this will likely experience a surge in demand as people start PvPing.
Leatherworking is getting distinctly more ilvl378 craftables than the other professions. The materials for the ilvl378 gear is mostly volatiles, Pristine Hides, and the usual Living Embers and Chaos Orbs.
When it rains, it pours
On top of all the demand for crafted gear, there will be a massive surge of demand for items that improve gear. Every piece of crafted gear made and used will likely get gemmed and enchanted. Some enchants are from standard enchanting materials, which will likely become more expensive (especially Maelstrom Crystals, which won't be churned out by farm raiding as much). Some enchants are made by other professions (like leatherworking's leg armors or blacksmithing's belt buckles). These actually share materials with the new gear, and will likely be a little more expensive to make. Additionally, cut gems and Heavenly Shards share base materials with blacksmithing gear.
On my buy list is:
Volatiles (all of them, especially fire)
Ore and bars (which I am prospecting and smelting before the patch for use in jewelcrafting and blacksmithing)
Leather, about a third of which I'm storing as Pristine Hides.
Enchanting mats, especially Maelstrom Crystals and Heavenly Shards
What about you guys? What are you stocking up on in preparation for patch 4.2?
Maximize your profits with more advice from Gold Capped as well as the author's Call to Auction podcast. Do you have questions about selling, reselling and building your financial empire on the auction house? Basil is taking your questions at firstname.lastname@example.org.