Guys to add to this it looks like http://www.exeltek.com.au/plantronics-backbeat-go-2-headset-… is back in stock. These are $129 in officeworks with case, price matching with exeltek will drop down to $75 - worth a try.
Good price here for the latest edition of the Backbeat GO. Even better if you price match at Officeworks (takes it down from 88 to 65.55)
Just done this in Sydney CBD with no issues - although I wouldn't count on the Pitt St store, none were on display and I had to ask.
Read reviews about the headphones, seem worth it for that price just to gym in. Or even just to add to your collection of other headphones you haven't used yet (cheers Harvey Norman). One day they might come in handy. Maybe dust them off and link to your laptop to play the steam games you will never look at again.
Enjoy!
Note: Link is obviously to the original price.
I've had a pair since they came out. Still going strong. Very nice sound for BT headphones. Great for going for walks. Battery life is OK - probably the only downside. Does have a deep sleep mode which holds charge for a long time.