for other ideas on the glyph market please follow the link to the free Croda's Inscription Gold Guide
As was the case in the Wrath of the Lich King, the lowest price herb is normally a new herb introduced by the new expansion and Cataclysm is no exception. For us Scribes that means we are buying Whiptail, Stormvine and Cinderbloom.
The primary reason for this is that Whiptail, Stormvine and Cinderbloom are relatively easy to gather and there is demand from Scribes and Alchemists for these herbs making them a good source of income for farmers. But the demand is more than matched by supply therefore keeping the price low.
Looking at my Reference Guide at the back of Croda's Inscription Gold Guide or the post on Herb to Gyph Conversions it can be seen that Whiptail gives more ink per stack than Stormvine and Cinderbloom and hence why Whiptail is normally found at a slightly higher price.
I am willing to pay up to 1gold 50silver per Whiptail though i normally pay about 1gold and only up to 1gold per Stormvine and Cinderbloom given Whiptail converts into more Inks and procs more Burning Embers to make Inferno Inks.
For Whiptail that means that my crafting cost per glyph is 10 to 15 gold each and for Stormine / Cinderbloom the maximum crafting cost per glyph is 15 gold each. Or, putting it another way, the cost of each Blackfallow ink is 3.33 to 5.0 gold each, and therefore the cost of any common ink to me is 3.33gold to 5.0gold each.
Indeed, when i look at herbs on the Undermine Journal only Peacebloom, Mageroyal, Liferoot, Silverleaf are cheaper in any reasonable quantity.
Worth noting these – often Lions Ink and Midnight Ink can be crafted cheaper by buying their associated herbs Liferoot and Mageroyal respectively rather than buying the Cataclysm herbs to craft Blackfallow ink to convert to Lions / Midnight ink. And indeed, that is why Lions Ink and Midnight Ink can typically be found for less than 5 gold on my server and often approaching 3gold each.
But, having all the herbs on your snatch list is a good idea. Once per week i often come across someone dumping their herbs for a low price.