DotA 6.80b Gold Exploit With Wards was already fixed in the latest version of DotA 6.80c.
- Pick any hero and completely fill its inventory with Ironwood branches
- Buy a courier and buy a set of Wards (doesn't matter Sentry or Observer)
- Buy an Energy Booster and put both wards and booster in Courier's inventory
- Move courier back to the Fountain so it acquires mana to use Wards. That's why we bought Energy booster.
- Select courier, click Sentry ward and target your hero standing with full inventory.
- Since, your hero has full inventory the wards will drop as a Yellow-book on the ground.
- Each time you use a single ward from Courier, you get Double (2x) wards in return
- Pick-up the dropped Wards (yellow-books) again using the courier and repeat the steps.
- And then sell the Wards for gold until you have gold to buy a 6x inventory.