How to tell if a watermellon tastes good?

Without buying and eating it first?

Vulcan mellon meld

A melon tester.  Imagine a drinking straw, but the width of like a coffee stirrer.  You can discreetly plunge this into a melon at the store and withdraw it, giving you a nice thin slice of melon to taste-test.

>>1
You see which mellon a nigra is about to buy then you run in and take it before they do