In order to provide any useful help with your question we are going to need to know what you consider a "reasonable" amount, and the rough date(s) of your return to the USA.
VAustralia currently has one-way fares from SYD or BNE to LAX for appr. $ 630 AUD ai. Last date at this price is currently Nov. 30, but I suspect it will get extended or certainly reappear for travel in March or April of 2010. Not what I would describe as "cheap" but one-way fares on this route are not known to be cheap.
There are several discount carriers with flights from Australia to SE Asia. Tiger, JetStar, and Air Asia fly from a variety of cities in OZ to SIN and KUL. If you book far enough in advance you should be able to get a one-way ticket from PER to KUL, or PER to SIN, or DRW to SIN for not much more than $ 100. SYD, MEL, or OOL to Asia will cost a bit more. You may then have more options for an economical one-way fare back to the USA.
People may be able to provide other useful suggestions if you provide your appr. travel date.