Remember the charm earrings you used to wear in fourth grade, when you made friendship bracelets out of string and cuffed your Cavariccis? Against all odds, they’re back, in superdeluxe form: Louis Vuitton and Cartier both created luxe versions this spring. If, however, you’re not prepared to pay anywhere between $690 and $31,000 for childhood nostalgia, head to Agatha, where these cheeky gold-plated or sterling-silver hoops cost a mere $30. That leaves you with plenty of cash to add additional charms—butterflies, your astrological sign, seahorses—at only $8 to $35 extra. (611 Madison Avenue, at 58th Street; 212-758-4301. And 159A Columbus Avenue, at 67th Street; 212-362-0959.)