King Charles, Prince William achieve major victory against Diana's brother Earl Spencer

Earl Spencer's new book price has reportedly been slashed, leaving King Charles and Prince William feeling victorious.

As per the latest reports, Diana brother's explosive memoir, Swan Song: Diana, My Sister, is now available at Waterstones in the UK for $19. This is half of its recommended retail price.

The rising problems around Earl's memory are making the British monarch and his son feel victorious.

For those unaware, Earl made a series of accusations regarding King Charles's relationship with his late Princess Diana in his new memoir.

“There is a feeling that the Palace doesn’t need to get dragged into a prolonged public fight with Charles Spencer because events surrounding the book are now speaking for themselves," a royal source told RadarOnline.

“Piers challenging a clear factual error, Charles having to apologize, and the prospect of legal action have inevitably raised questions about the book’s accuracy,” the insider continued.

The confidant added, "From a PR perspective, people around the King and William feel the argument has effectively been won without them having to say very much at all – and they feel like they are having the last laugh about the whole affair, seeing that the price of his book has already been slashed so dramatically.”