Remember Glowcaps in Zangarmarsh? These little mushrooms are all over the place (and probably really annoying to those herbalist who were trying to farm “real herbs”). So whats so special about them? They can be used to purchase cooking recipes off the Sporeggar Quartermaster that can be sold on the Auction House. Recipe: Sporeling Snack Takes 2 Glowcap and Recipe: Clam Bar takes 1. These sell on the Auction House for around 12-30g depending on your server and supply.
But why would people want to buy these recipes if they are so easy to get? Like many other gold making ideas, it is because either the person is too lazy to look up the item on where it came form, or to them it isn’t worth their time to go to Zangarmarsh to pick it up. Another reason is people are looking to get achievements for cooking recipes, this results in them looking around the AH to see what they are missing, hence a purchase of one of your recipes.
So why should it be worth your time? You can collect about one Glowcap per min. Each Glowcap is “worth” about 6g min each. This equals about 360g an hour.
Now you will not sell all of them right away. List 2-3 at a time and store them on a bank alt. It is much easier to grind out several of each and store them, than it is to go back to zangermarsh every time you need 1-2 recipes more.