In WotLK, many people learn the Inscription, and they may need lot of low-grade herbs, we can make gold with this.
First of all, we have to know which herbs they need.
Inscription
1 - 75: Peacebloom, Silverleaf, Earthroot, Mageroyal
76-100: Briarthorn, Swiftthistle, Stranglekelp, Bruiseweed
101-150: Wild Steelbloom, Grave Moss, Kingsblood, Liferoot
151-225: Fadeleaf, Goldthorn, Khadgar's Whisker, Wintersbite
226-250: Wildvine, Firebloom, Purple Lotus, Arthas' Tears, Sungrass, Ghost Mushroom, Blindweed, Gromsblood
251-300: Golden Sansam, Dreamfoil, Mountain Silversage, Plaguebloom, Icecap
301-350: Terocone, Dreaming Glory, Mana Thistle, Nightmare Vine
1-75, the Earthroot are cheapest
76-100, the Bruiseweed are cheapest
101-150, the Kingsblood are cheapest
151-225, except the Goldthorn, the others are cheap
226-250, the Sungrass are cheapest
251-300, the Dreamfoil and Icecap are expensive
301-350, the Terocone are cheapest
So we can buy Earthroot, Bruiseweed, Kingsblood, Fadeleaf, Khadgar's Whisker, Wintersbite, Sungrass, Golden Sansam, Mountain Silversage, Plaguebloom
The other herbs we can use Herbalism to collect.The most valuable are the most in-demand 251-300, that means we can prepare to sell Golden Sansam, Mountain Silversage, Plaguebloom.
Where can we get these herbs?
The answer is Felwood, no one will compete for resources, herbs throughout Felwood are all yours, that means you can make a lot of WotLK classic gold from the auction house.
Have to be aware of We only buy and collect cheap herbs, because no one wants to hoard these herbs, only us. Than we can get almost all the cheap herbs incomes, get more WotLK classic gold.
Finally, I hope that everyone who sees this article can make more and more WotLK classic gold.