Making Some Gold

[Kayley]

Righto, people here with more info, halp.
I've never been in a position to stack anything up before an expansion goes live.
What sort of things (if anything) should I stock up on?

I mean i'm told professions are changing, so should I not stock up on all the various enchanting dusts? I dunno these things.
PLAISE HALP

*edit*
A week ago Hypnotic dust sold for 220-240g a stack, now it's at 150-170g. I have no idea if these sorts of things become more valuable or lose value when a new expansion hits T_T;
Apart from googling do any of you have any decent sites with this sort of info?