Burberry Prorsum Children’s Trainer Sneaker Size US 8.5. Burberry Prorsum is the most expensive out of the three Burberry brands; Prorsum, London, & Brit. These were only used once for professional portraits, have been in the box since. Unisex. Classic plaid with gold plated Burberry laces, Burberry logo on rubber heel and sole. Comes with dust bag, original box and tag strand. Retail: $470.