Spotted this today, a lot better than the $3+ they usually go for individually, this brings them down to $1.67ea.
Checked the first lot of PnS on Grocer, couldn't see any other stores that also have this deal, but some do have them for $1.79 (Henderson) or $1.99 (Botany) so not too far off.
Available flavours were:
Ginger Lemon
Wild Berry
Blood Orange
Raspberry Lemonade
a while back whyknot had 2x750ml for $5, but they went quite quick, might have to resort to these.