The next cheapest brand at the retailer is a packet of pads from Always, which, sold for $2.
Tania Benyon, chief product officer for The Warehouse Group, told Stuff that it would be a long-term initiative and that the company was looking to add tampons to the range in the future.
Many commenters were happy that such a large company could make this step towards solving such a big issue.
"Great to see a retailer stepping up and providing very affordable sanitary items."
One fan also suggested they add this to their ongoing donations process.
"Please have these at the counter as your 'donate a pack' sale instead of the donate a dollar to xx etc."
You can find the products online and in-store now.
The Warehouse announcement comes after an informal poll made by the Herald showed that an overwhelming majority of New Zealanders would like to see public schools in the country offer free period products to students.
The post on the Herald Facebook page asked people if they believe New Zealand should follow England's lead and introduce free period products in public schools.
The poll received more than 11,600 responses in just five hours. At that time, close to 11,000 people had voted "yes", while 813 voted "no".