Prince Edward’s recent choice of wardrobe has caused a £200 product to sell out online. On his recent trip to South Africa, the prince matched a blue suit with a Hermes silk monkey and crocodile tie. The tie has now sold out on Hermes’s website as the duke shows once again how clothing worn by a royal can boost a brand’s business and awareness. The prince sported a navy blue tie with small, repeated images of a blue monkey dangling from a vine above a snappy green crocodile’s snout. Last month the prince flew to South Africa for a two-day working trip before heading to St Helena for a four-day…