Explain like I'm 5 why food is so expensive

I had an a heated discussion with my father in law about why the price of meat and dairy in New Zealand is so expensive, considering we are producing so much of it. I blamed us getting the short end of trade agreements, while he was saying it didn't affect our prices and was mainly caused by distributors.

So can someone explain why a block of butter at the supermarket is $8 and often the cheapest one is from France ?

Also, why our beef and lamb keep on going up in price so much, while the farmers are literally next door to large cities?