By Susan Edmunds of RNZ New Zealand is exporting much of its premium product - and then importing cheaper options for New Zealand shoppers, economists say. Pak'nSave's move to sell United States butter more cheaply than local butter has prompted conversations about how it is possible for imported items can be offered at a lower price than those produced in the country. But trade data shows that butter is far from the only item that has a higher price when it's made in New Zealand. Cat and dog food was cheaper when imported. Dog biscuits - most imported from Australia, Canada, and China - were 87.6 percent cheaper than the export price of New Zealand products. Water with added flavouring was also 25 percent cheaper when brought in from countries like the United States than the local product was exported. Jams and marmalades were 21.9 percent cheaper when imported - often from Chile and Poland. We also import cheaper wine than we export - among still wines, imported products were 25 percent cheaper.…