I am not sure if this is Nationwide. I got it from the Minto, NSW store.
The 500GB 2.5" Medion drive is $45 at ALDI. I was told this when I failed to get the 1TB today. I did not ask how long the price lasts for.
Looks like a good price to me. Next cheapest 500GB is around the $65 mark.
The drive is USB powered. More details about the drive can be found here: http://www.ozbargain.com.au/node/19669
I have attached the receipt for confirmation.
mod - added a bit more detail to the title, now that it doesn't seem to be available at all stores
VERY good price. Waiting to hear more, I will also check my Aldi tomorrow and report back. Though I'm not expecting my local one to have any.