Half price $2 barista coffee (Vittoria) @ Woolworths Chatswood with opal topup.
Min topup normal $10.
Just got one, not too bad.
Not sure if other stores.
Got my coffee made while I grabbed what I needed, quicker line than the opal machines downstairs sometimes.
Not as cheap as seven eleven to be sure, but cheapest coffee at the interchange if you can't be bothered walking for 2 mins.
Woolies have now got a cafe there again? I swear every time I walk in something has changed.