I saw this double walled mugs in the previous post
https://www.ozbargain.com.au/node/202941 and sold for $2.00 each.
I found it cheaper in Burwood VIC, $1.20 only! BARGAIN!!
https://www.dropbox.com/sc/gvlibh6z5qo4n1c/AADGG4cJnpKhwwQ2o…
I bought 4.
Dang, and I thought $2 was cheap. I have a feeling it might be a store-specific discount, but good find nevertheless!