Covers Internal Oscar de la Renta gown, $5,990. oscardelanreta.com. Balenciaga ring, $395. 212-328-1671. Giambattista Valli Haute Couture ball gown, price upon request. giambattistavalli.com. Welcome to the Issue Page 45 Cartier Magnitude High Jewelry transformable necklace/brooch, price upon request. Table of Contents Page 50 Chanel Fine Jewelry Blé Maria brooch, price upon request. Page 56 Gucci High Jewelry brooch, price upon request. Page 66 Louis Vuitton Les Armoiries brooch, price upon request. Must-Haves Page 81 Harry Winston earrings, price upon request. Manolo Blahnik sandals, price upon request. Page 88 De Beers rings, $16,600–$63,000. What to Buy Page 90 Ana Khouri earrings, $16,100. Dior Timepieces watch, price upon request. Gift Guide Page 94 Dior Fine Jewelry ring, $600,000, and earrings, $183,000–$345,000. Page 96 Tiffany & Co. bird’s nest, $80,000. Monse x Gigi fedora, price upon request. Irene Neuwirth…