I know this is common sense but on my server lucky noone does this and everybody thinks Formula: Enchant Weapon - Executioner - Item - World of Warcraft is a bit of value.
Dealer Jadyan in Netherstorm sells Formula: Enchant Weapon - Executioner - Item - World of Warcraft receipe with unlimited stocks.
He can be found Dealer Jadyan - NPC - World of Warcraft
What I basicly do is buy like 20 Recipes go back and sell them in the AH or while spamming in Trade Chat.
Usually sell them for 100g each, but can be also sold for a higher price.
I do this while doing arena, bgs, enchanting and whatever you guys do in the main cities.
and sry if it is a repost. couldn't find it.