40 Years On, A Detailed Look At Princess Diana's Dream Of A Wedding Gown British Vogue Many of Princess Diana's dresses have been auctioned off for between $500,000 and $1 million. The most expensive dress worn by the late royal to be sold at auction is a 1985 Amazon.com: Luxury Princess Dress Costumes with Shining Long Cape Girls Birthday Party 2T 3T : Clothing, Shoes & Jewelry Glamorous 3D Flowers Ball Gown,Princess Dress,Sweet 16 Dress Y2320 Simplepromdress