Koss Porta Pro headphones are arguably the best headphones you can buy for under $80.
MyMemory has 24% off on them right now
You can get a further 5% off with this code: VE5AW12
Total including shipping comes to: £23.79 (AUD $37.80)
MyMemory sale page:
http://www.mymemory.co.uk/Overhead-Headphones/Koss/Koss-Port…
Manufacturers specs page:
http://www.koss.com/en/products/headphones/on-ear-headphones…
Reviews from headphone/audio buffs:
http://www.head-fi.org/products/koss-portapro-headphones-sem…
That price has gone up, when I ordered mine from them it only cost around $30. They jacked up the price for that last 30% off sale or something and never dropped it back down.