American millennials may have ruined mayonnaise, but at least they haven't launched an avocado black market. That's what's happened in New Zealand, as low avocado harvests has driven the average cost of one fruit to $3.30. New Zealand refuses to import the toast-topper, jacking prices up 37 percent in the past year, The New York Times reports. Guacamole lovers have tried to avoid high prices by growing their own avocado trees, but they are often put on a waitlist at nurseries, the Times says.