Winterspring - Frostmaul & Shardtooth E'ko Farming Location (Classic - WoTLK)
One of the highest gold per hour farming locations in the entire game is in the southern portion of Winterspring at the Frostmaul Giants and Shardtooth Bears. In order to get the most out of this location you will need the Cache of Mau'ari item which is rewarded to you for completing the "Luck Be With You" quest in Winterspring.
The Frostmaul E'kos are used for the Attack Power Juju which stacks with all other buffs in the game and will be desired by Melee DPS classes and Tanks from now until WoW Classic ends. Many of the min/maxers like to use this buff during raids which means the item will retain value forever. If you play on a server with a large community of min/maxers then this item will be even more profitable for you to farm.
Similarly, the Shardtooth E'kos are used in a Juju as well. These items are used for the Fire Resistance Juju and aren't as valuable as the Frostmaul ones, but are still very valuable for players on the Ragnaros/Nefarion fights. If you're on a server where there are still guilds progressing through these fights then this item will be more valuable for you than on other servers.
Along with the E'ko items that drop here, there is one more drop that you'll want to keep an eye out for - Greater Frost Protection Potion. This is an Alchemy recipe that only drops from the Frostmaul Giants and can net you a decent chunk of change on the Auction House.
Of course you'll also find a lot of different herbs and mines at this camp if you're either an Herbalist or a Miner.
Winterspring Mines: Rich Thorium, Small Thorium, Mithril
Winterspring Herbs: Dreamfoil, Icecap, Mountain Silversage, Black Lotus