Arcane Dust
The Arcane Dust market is probably one of my favorite markets when it comes to messing with the Auction House. The reason it is my favorite is because it is usually always the most extreme market. What I mean by this is Arcane Dust prices are always extremely high or extremely low. Much like the Netherweave market someone always floods it one day with dirt cheap materials and then everyone scoops it all up, stops farming it and doesn't need anything for the next few days. Then out of no where prices just take off and stacks of Arcane Dust go from 30g a stack to 70 - 80g a stack.
When you spend some time on the Auction House you will start to notice this with the Arcane Dust, if it is the same on your server that is. Depending on how much gold you have I recomend buying out a few stacks when it is low in price and waiting for it to skyrocket again. A good safe amount to buy is 4 to 5 stacks, even if you don't make as much profit as you had hoped you still will make some gold. Below is the average type of deal I see on Arcane Dust when it drops in price.
Now this isn't the best deal I have ever seen on Arcane Dust, well, actually that is a lie, the first item on the Auction House for 4 Arcane Dust for 4g is an amazing deal, I bought that immediately after taking this picture. The rest of them are just mediocre deals at best. Sure you can make a few gold off of buying all of them but not enough for it to catch my attention. Just like for Greater Planar Essences I leave those Arcane Dust up as bait to catch people that undercut them even more, like the first guy in that picture.
The only way I would recommend buying out all the Arcane Dust for 2g each is if you wanted to clear room for your Arcane Dust for something like 3g each. Just be patient and keep in mind that the Arcane Dust market always winds up jacking itself up seemingly at random and you can sell your Arcane Dust for insane prices.
Now that picture is Arcane Dust selling in full stacks, not singles because that would be completely absurd. I see the prices go that high usually three or four times a week and I usually save my Arcane Dust until then, buying out anything lower throughout the week until I wait for it to get jacked up. The only way I ever unload my Arcane Dust before the prices get that insanely jacked up is if I get too much of it and it is starting to clog up my inventory.
Now on the other end of the spectrum Arcane Dust could be selling like hot cakes on your server and you just can't get enough of it. If you have an abundance of Netherweave and access to someone with Tailoring you will be able to make Netherweave Pants and Disenchant them. Below is all of the information you need to know about making Netherweave Pants.
Bolt of Netherweave x 6 (30 Netherweave)
Rune Thread x 1
Result: 
Netherweave Pants
Now the reason you will want to make Netherweave Pants over anything else is because of their Disenchant table. Out of all the greens you can make with Tailoring, Netherweave Pants are the cheapest and have the best DE table. Below is a screenshot of the DE table you can find with Netherweave Pants.
Now even though that says the maximum Arcane Dust you can get is 4 I very commonly get 5 and that is without the Bountiful Bags perk. As far as Greater Planar Essences go I've never seen more than 2 and assume anything past that is impossible, unless of course you have the Bountiful Bags perk. Below are how much I can usually get per unit for both Arcane Dust, Greater Planar Essence and Large Prismatic Shard.
Arcane Dust (3g each)
Greater Planar Essence (24g each)
Large Prismatic Shard (4g each)
If you have a guild at level 23 or above you will have the Bountiful Bags perk, which means you will pretty much always profit without a doubt from Disenchanting Netherweave Pants. Without it you will need to get at least one Greater Planar Essence or four or more Arcane Dust to see profit above what the stack of Netherweave would sell for. For this reason I only recommend doing this if you have Netherweave just piling up and not selling for the price you want it to. Or, of course if Arcane Dust is going for insane prices on your server like 3 or 4x the average.
I need to warn you though, don't convert all of your Netherweave into Arcane Dust, because what happens then when the Netherweave Cloth starts to sell again? I made this mistake because I had at least 100 stacks of Netherweave in my mail taking up space so I made it all into Arcane Dust, sold each stack of Arcane Dust for 70 some gold, which I was happy about but then Netherweave Cloth's market started to pick up again and I couldn't take advantage of it. I learned from my mistake, hopefully you don't need to make a similar one to learn from it and you can learn from what I just said.
Botanica Farming For Arcane Dust
Arcane Dust Video
Arcane Dust Tips
- Never panic and unload your Arcane Dust for a low amount
- If the Arcane Dust market is through the roof or if the Netherweave Cloth market is extremely low make Netherweave Pants and Disenchant them
- Never stop Disenchanting greens because you think you have too much Arcane Dust
- If there is a level 70 twink guild on your server enchant scrolls with high end level 70 enchants and try to sell them. Or directly offer to enchant the guild's gear.