Duracell Xbox 360 Play & Charge Kit $12.95 + free shipping @ Gamesmen
It’s great cause then you don’t have to waste money on batteries and if it dies you don’t have to run to the store. It comes with a 3m charging cable so you could just plug it in to charge and continue playing. It has 30 hours of play time and come pre-charged!
JB Hi-fi have it for 20.97 inclusive of shipping fees while Oz Gameshop has it for $25.49 with free delivery. So, Gamesmen has the best price.