In before people scream REPOZST!!!!??!?!, this is not the trick with buying titanium ores now and selling them high when 3.2 hits (which everyone is doing today causing the Titanium price to just about tripple on my server).
Another thing you can do to get the gems is buy them with Badges of Heroism.
Badges of heroism are already used for buying 3 things:
1. Red Rare gems
2. Frozen Orbs
3. Abyss Crystal (De those 15-badge trown weps into 1-2 abyss crystals by enchanters, fairly wellknown trick)
With the new Epic gems implemented, this means everyone is gonna buy the epic gems with their spare badges instead of either of those.
In due course of the epic gems implemented Scarlet Ruby's will drop in price, but because people will be more likely to buy the epic gems, nobody is gonna buy Frozen Orbs and, to a lesser extent Abyss Crystals.
I think everyone knows that Ench mats skyrocket after a new raid comes out, meaning alot of people will pile every kind of enchanting mat they have on the AH the day of the patch, thus kinda waisting your profit on Abyss Crystals.
But the frozen orbs, currently up for ~40g on my server, will steadily go up in price abit, im expecting easy ~60g sales when the patch hits, so currently im stacking those orbs, got 3 stacks atm.
This is a nice way to make a pretty decent profit for yourself