The perceptive among you will notice there is no limit on personal importation of good-condition dragonfruit.
I got funny looks when I went into a supermarket to buy a large carrier bag full of dragonfruit during a 12-hour connection in HKG.
I got a lot of brownie points from Ms Flatlander and Miss Flatlander. They have a great liking of dragonfruit and can easily eat a couple of fruit each day for a week, which is how long they last when fresh.