Jewelry expert's undercover to show Tiffany overcharges for diamonds

Diamond expert Jacob Worth, founder of I Want What It's Worth, went undercover at Tiffany & Co, Cartier, Van Cleef and Harry Winston He claims the high end stores sell identical diamonds to those found in Costco Worth compared simple round cut solitaire diamonds in each store He says that the luxury retailers put a mark up of up to 336 per cent A jewelry restorer has gone undercover at some of New York's most recognizable diamond stores to 'prove' that customers are being ripped off.