Boost Nero Android 3G Phone at BigW at $24.50 (half price from $49)
I haven't had experience using a Boost Prepaid Mobile, but I assume they work with Telstra sim card (happy to be corrected).
If so, easy way of accessing Telstra billing on Google Play Store so you can make use of the $1 Telstra Starter Kit You may have gotten from Woolies or Coles.
Icon Nero
The Boost Mobile Icon Nero is the killer value entry level smartphone with Android™ JellyBean OS features and a 1GHz dual core processor. On top of that, the Boost Icon Nero features a 3.5” screen and 2MP camera for capturing and sharing all your favorite moments.
Android™ JellyBean OS
1GHz Dual Core Processor
3.5” Screen
2MP Camera
All Boost Mobile phones come with a $10 starter credit in box and are locked to the Telstra 3G Mobile Network.
Screen a bit on the small side, I think 4" is a minimum these days