So many people swear by dry shampoo & this is one of the best brands you can get. They aren't being advertised on special but at Christmas I bought a same size bottle for $9 at the warehouse so $7 is about the cheapest out there!
Comparative:
New World $11.99(ishopnewworld.co.nz)
Farmers $11.99(farmers.co.nz)
Kmart $11(kmart.co.nz)
Countdown $10/12(shop.countdown.co.nz)
It's currently buy one get one half price. Amazing deal!