Just grab a 30-day (month to month) data package, $19 for 2GB and get the Pocket WiFi 2 for $34, sounds like a good deal.
Not sure how much the unlock fee is though.
Update:
Unlocking: check out http://www.dc-unlocker.com
Around A$12-14 to unlock the device using DC Unlocker's client.
Free Unlock (NOT verified by poster)
http://m0nkeycheese.blogspot.com.au/2011/04/australian-huawe…
Vodafail? Really? I've been stung by the company's poor network but it's childish to to namecall the company in a bargain post.