I'm surprised with the $99 listing on the website as in store they are $79.
This product has been posted a few times of late;
http://www.ozbargain.com.au/node/88986
http://www.ozbargain.com.au/node/83023
so perhaps consider this an update.
Have a great year.
FYI - It's not a huge amount of effort to open these up and to rip out the drive inside (it's a Barracuda 7200rpm SATA drive). I installed one of these into my dad's computer - it's cheaper than going going to MSY to buy a bare drive!
(I'm sure the warranty is destroyed but oh well!)