In addition to the great sentimental value that the ring of Kate middleton, the piece has its own value. In 1981, when the Prince carlos bought it for his then fiancée, the deceased Princess Diana, paid 47 thousand dollars. The jewel, in a gentlemen’s agreement between the prince william and the prince harry, happened to Kate when she got engaged to William in 2010, as he was the first to get engaged.
With time and the history that the jewel has in the family, the piece made up of a sapphire surrounded by diamonds was valued at 500 thousand dollars. Much more expensive than your own Queen Isabel, with a value of 168 thousand dollars.