Collins are just one of Kobo's Australian partners, and the other partner (Pearson's) won't be getting either the Kobo Touch or Kobo Vox anytime soon. In fact, the Borders.com.au website doesn't even mention the Vox; the only new Kobo mentioned is the Touch and they won't have it until 30 November.
I've also checked WHSmith and Fnac, Kobo's other two big name partners, and neither mention the new Kobo Vox. That would suggest that Collins got the Vox first becuase of the timing. They're just beginning to carry Kobo eReaders, and that may have given them the chance to push and get all the models at once - even the new one.
Now, if you read this far then you might have noticed the one detail I hadn't discussed yet: the price. Collins listed the Vox for
$199 $249 $299. Note that AUD and USD are in near parity, and taxes alone don't justify the increase.
The US price for the Kobo Vox is the same as that of the Kindle Fire. But in Australia, where the Kindle Fire isn't available, they're pricing it for $1oo. That should tell you something, and it's not good. Kobo are likely taking a loss on each Vox sold in the US. They're losing money just to stay in the market.
This might be a sustainable option in the short run, but Kobo don't have the resources to keep this up. Heck, I'm not even sure they can afford to this even in the short run. They're a startup and don't have the resources of Amazon, B&N, or Sony.