Not really a "deal", so I'll put it here.
This year is the last time the Girl Guides will be selling their biscuits. Online stock has already sold out (although they do give an email address to contact the 'Biscuit Team'), but according to their webpage and the ZMOnline webpage, the final sales of the biscuits are:
Christchurch: 8:30am - 5:00pm, Monday 8 - Friday 12, April, 2019 at the GirlGuiding National Office, 5 Sir William Pickering Drive, Burnside.
Auckland: 9:00am - 5:00pm, Saturday, 13 April at the Auckland Guide Centre, 132 Grange Road, Mt Eden.
Christchurch: 9:00am - 12:00 noon, Saturday, 13 April at the GirlGuiding National Office, 5 Sir William Pickering Drive, Burnside.
There's bound to be queues and they sell out fast (if there's even any left!), so get there early.
Apparently the Girl Guides won't be selling them any more simply because the parents are too busy (or too lazy) to help out their kids.
I don't know why the Girl Guides don't aren't doing a deal with the company that already makes the biscuits and the supermarkets to sell them in stores with a "20c (or whatever) per sale" going back to the Girl Guides. There are already similar promotions for other organisations.