Long time looker, first time posting :)
Temple and Webster has this ErgoHuman chair on sale
If you stack with Shopback's 20% cashback + 15% westpac lounge bonus cashback (capped at $50 each) the price is brought down to $529 + shipping ($43.59 for me in Mel) which is slightly better than this popular deal around 3 yrs ago.
Hurry as the Westpac lounge bonus cash back
ends tonight (27th Oct).
Based on the comments in the deal above, this seems to be genuine Ergohuman chairs and looks like most ozbargainers who bought this were happy with their purchase.
I have ordered one and delivery estimate to metro Mel is around 3rd Nov.