My first post, so please be nice. :) Was browsing Amazon for headphones and noticed they have 50% off selected headphones/earbuds, including the Sennheiser CX 300 II Precision earbuds for $29.24US (was $79.95). These are one of the few discounted products in the sale that ship to Australia. When added to the cart, shipping should be $5.65 for a total of $34.89, or about $42AU.
For comparison, the cheapest I could find at a trusted business was at Officeworks for $69. Everywhere else is selling between $80-$100. Sold and shipped by Amazon, so these should hopefully be legit as I'm aware there are a lot of fakes out there.
For extra savings, if there is anything else you want from Amazon before the end of the year that makes your cart total $100US or more, get free shipping by using this Amex deal: https://www.ozbargain.com.au/node/170818
Edit: product now no longer sold and shipped by Amazon and new seller does not ship to Australia, so have expired this deal.