Decent price (lowest ever was $18 per CamelCamelCamel). Looks like Amazon are price matching current Woolworths half price sale.
Deal covers Classic, No Sugar, No Sugar Vanilla, Diet and Caffeine Free Diet. Classic and No Sugar are also available in a smaller 6 bottle pack for the same unit price.
Remember you can Subscribe & Save to get the lower price and then cancel later. Looks like no cashback from Cashrewards or Shopback for this category. But you can still stack with 3% discounted eGift cards from Suncorp.