None of the suggestions above really suit your budget but if you're capable of sprucing for the extra, I think they are saying it's worth it.
I would say with that kind of budget you're better off getting a decent headphone first then spring for a amp/dac once you have a bit more money down the track.
For example, a HiFiMan HE-400 doesn't really need amping to sound good and can run off a laptop straight without too much issues. It costs $419 from memory in Australia (can be had for $409 from minidisc.com.au but not sure about reliability). Then you could get the O2 DAC/Amp or something similar once you have some more money.
That's my 2c.