A couple of links to some decently priced cases.
First comes from a mailout I got with a voucher. They give the https://www.cellarmasters.com.au/50off URL and encourage you to use your $50 voucher there. Even without the voucher (unique code), $120 for a dozen wines is fair value. Not sure how I got on this list but $70 a case is great.
Second is from Westpac but doesn't seem targeted, https://www.cellarmasters.com.au/westpacrewards most are sold out but this promo runs until May 2020 so they might restock. Has been posted before.
Cellarmasters offer free pickup at BWS or $10-$12 delivery per case.
Occasionally ShopBack or CashRewards bump up CM cashback so you could wait for a steeper discount if you stack with them. You are not using a coupon so can't see why it wouldn't stack.
There are twice annual offers from Cellarmasters that are 50% off everything. This isn't one. Waaaaaiiiitttiiinnnngg .. :-) .. !! Here's an example:
https://www.ozbargain.com.au/node/480072