Five Water Balloons

A man had five water balloons, That he had kept as souvenirs. He stored each one in its own box, Where they’d survived for many years. One box was made of platinum, Studded with Rubies all around. Inside it was lined with ermine, That’s where the red balloon was found. Another box was made of gold, Studded with diamonds round about. Within it was lined with velvet, The yellow balloon’s box was stout. A silver box held another, And there were emeralds set therein. The box had a satin lining, And the green balloon dwelled within. Then there was an ivory box, Set with sapphires on every side. It was lined with the finest silk, The blue balloon was found inside. And last there was a wooden box, Its creator was quite adept. Skillfully carved from knotty pine, That’s where the pink balloon was kept. So when you look at every box, And the riches of which they boast, Which of the five water balloons Do you believe is worth the most? And if you chose between the five, Then you have made your choice too soon. What do boxes have to do with The worth of a water balloon?