With Cata coming in 3 days there are a lot of people out there who are panicking thinking that all their low level mats will not be worth anything once it hits. The variety of those people can range from 80s selling items their alts have picked up and even first time players who don't realize what's about to happen. If you are one of those people who aren't stocking, barely stocking, or kinda stocking then you fall under the category "don't realize what's about to happen" and maybe even "don't realize what's happening now." What i have noticed on my server are surges of low level mats being posted in bulk for less then half normal price.
The area that this has been happening to the most is the herb section. The great thing about herbs is that they are heavily used in 2 profession; Alchemy and Inscription. If you have an inscriptionist you should jump all over these herbs to mill. the math i have come up with is that buying low level herbs under 15g will make me profit (5-6 inks per stack).
Since cata is so close i have decided to stop milling everything that i buy just in case there is a boom of alch levelers who would need the raw mats. Leaving the herbs in its raw form gives you more options then just milling because you can turn around and re sell raw, you can mill and sell the pigment and/or inks, or you can even go as far as making the inks into glyphs. Having a balance of herbs both for inks/glyphs and alch. you will most likely generate the most profit.
Think of this scenario... all the people who are stocking herbs most likely did it to mill into inks/glyphs to save space, so when cata hits every ones inks/glyphs go up on the AH and there are no raw herbs to support the players leveling alchs. Since there is no outside support for the alchs the only herbs on the AH will be from the new toons. Demand will surpass supply and the price will inflate. This is where you come in: if you took the time to hold on to the raws you now have the option of surfing the inflation wave or selling them as glyphs. You choose your own destiny from here.
I do advise to stay away from peacebloom, silverleaf, and earthroot as they take away your inscription option.