A bustle of butter-buying at Auckland's Costco - where it costs $10 a kilo.

Stats NZ figures show the price of a block of butter has soared 65 percent in the past year.

Videos on social media show shoppers piling boxes of the spread into carts at the bulk-buy supermarket.

Former Costco managing director, Patrick Noone, says the store's very unlikely to try to stop bulk buying. 

He explained they did it once when eggs were short - but if they can supply it, they'll let people buy as much as they can.

LISTEN ABOVE