Tiger Airways - Prices From $28 One Way
Tiger has some cheap one way flights in the summer sale. $28 seems to be the lowest priced flight, though it's advertised from $50+ (see post below for example:)
Fully inclusive, one-way, hand baggage only, payment by Australian-issued Mastercard Debit card only*
* Buy between 06 Jan 10 and 11 Jan 10, or until seats sell out. Conditions apply.
** Flight Combo via Singapore.
***Flights to and from Brisbane are subject to regulatory approval.