I found this over at the Whirlpool forums and tried it myself so can confirm it can be done.
Basically EB are selling the Steelseries Dota 2 mouse bundle which comes with a Steelseries Kana mouse worth $50, a mini mousepad worth $12 and a digital "Kantusa Scrift Sword" code. This digital item sells for USD$40-42 on the Steam store which after Steam takes their cut gives you about USD$35 in your Steam wallet. So essentially you're getting a free mouse and mousepad and AUD$44 Steam credit for just AUD$36.
http://steamcommunity.com/market/listings/570/Genuine%20Kant…
There still seems to be quite a bit of stock at EB games, nearly every store at the Gold Coast has it. You can input your postcode on the EB website to find out where there's stock. When I went there they only had one left though.
Also you will need to install Dota 2 (6.6GB) to sell the item on the Steam marketplace.
Just sold mine and received $45 USD after steam took out the fees.