As of my last knowledge update in September 2021, the cost of a ticket for the Harry Potter Studio Tour in London varied depending on factors such as age, time of visit, and whether you purchase any additional packages or experiences. Please note that prices may have changed since then, so I recommend checking the official Warner Bros. Studio Tour London website for the most up-to-date pricing information.

As of 2021, the general ticket prices were in the range of £47 to £53 for adults and £39 to £45 for children (ages 5-15). There were also family and group packages available at different rates. Additionally, there were options to purchase enhanced experiences, such as the "Deluxe Tour" or "Complete Studio Tour Package," which included extras like a digital guide, souvenir guidebook, and other perks.

To get the most accurate and current pricing information, I recommend visiting the official website of the Warner Bros. Studio Tour London: The Making of Harry Potter or contacting their customer service directly.