With this Gold Farming Method you will be farming in Act 3 Nightmare. With decent DPS you can one-shot regular monsters and two-shot elites. You will start out at the Bridge of Korsikk and finish up by killing the boss Azmodan. You will kill tons of monsters and that is what makes this method worthwhile.
The entire run usually takes me on average about 23 minutes and I make anywhere from 112K to 150K Gold per run. Sometimes I continue on to the Keep Depths Levels 1-3 as I still have my 5 stacks of Nephalem Valor. There are a ton of monsters in the Keep Depths as well and you will continue to average at least 5K Gold per minute.
Aside from farming at the Royal Crypts (Recently nerfed), this was the second best way to farm gold in my opinion. Blizzard recently released a patch that decreased the amount of gold you get from Urns in Act 1 so now this may be the best method to obtain gold.
Steps#1. Get Gold Find Gear- You can find really cheap gear on the auction house (Pieces each under 20k Gold). Also look for gear with Pickup Radius, this will allow you to collect gold from a distance and save you a lot of time in the long run. If you are lucky you will find Gear with Gold Find, Pickup Radius and your character's Offensive Attribute (E.g. Intelligence, Dexterity, Strength). Without spending a fortune you can easily get your Gold Find % up to 150%+. I have around 210%, but I have seen players with even more than that.
#2. Nephalem Valor- You can easily acquire 5 stacks of Nephalem Valor in Nightmare. By the time you get to the Siegebreaker Boss at the end of Rakkis Crossing you should have 4 if not 5 stacks of Nephalem Valor. Kill Elites just before Rakkis Crossing or go to the Underbridge (If it is open), which is right before you get to the Siegebreaker.
#3. Use AoE Abilities- Area of Effect abilities may not do as much damage as single target abilities, but you are farming in Nightmare so it doesn't matter. Your AoE Skills should still one-shot most enemies and they will be most efficient when dealing with large packs of monsters. When I farm I use my Witch Doctor's AoE ability Acid Cloud with the Acid Rain effect to increase the radius.
#4. Increase Movement Speed- Faster runs means more Gold per Hour. You can buy boots that give you extra movement speed and there are even some weapons that increase movement speed as well. Make sure you also utilize each Class' skills that can Increase Movement Speed. Each Class also has its own Movement Ability. Speed is Key!
Quick Method OverviewAs you farm A3 Nightmare be sure to pick up the Magic and Rare items you find. They may not be worth anything to you, but you can sell them to Vendors for around 250 Gold each. Make sure your inventory is full before you go to sell items. Reducing downtime is very important when trying to make efficient Gold Runs. Track your starting time/ amount of gold and then check your finish time/ amount of gold. Let me know if you have any questions, comments or concerns in the comments below. Good Luck!
If you still need more Gold Tips check out Diablo 3 Gold Secrets.