Seems to be the best deal available at the moment when comparing Sony AU, Kogan and JB Hi-Fi.
However, I have read of someone getting them for $25 in this post.
Edit:
As per comment Klee’s comment, right now the cheapest price for these ear buds are at Amazon AU:
I was able to get them that cheap by combining the JB HiFi’s 40% off Sony headphones + the $10 off coupon from JB HiFi’s receipt phone number deal.
They were originally $59.95, then 40% off was $35.97, then $10 coupon applied to bring it to $25 total.
I may have referred to the price of the wi-c310 (which looks identical) at one stage and got the calculation wrong.