EDITORIAL USE ONLY. NO MERCHANDISING Mandatory Credit: Photo by Ken McKay/ITV/REX/Shutterstock (8459186ay) Chris Riddell 'Good Morning Britain' TV show, London, UK - 02 Mar 2017 A MILLION HARRY POTTERS Chris Riddell Parents will splash out almost GBP 400,000 on fancy dress outfits for their children to wear on World Book Day, according to new figures. Research by eBay.co.uk predicts British mums and dads spending more than GBP 386,000 on character costumes to be worn at school today. Children are encouraged to dress as their favourite book character for the day.