Who is the most expensive player Arsenal have ever sold?

Have you ever wondered about the financial transactions that occur in the world of professional football? One of the most intriguing aspects of the game is the buying and selling of players, and it's fascinating to see the prices that clubs are willing to pay for top talent. With that in mind, I have a question for you: Who is the most expensive player that Arsenal Football Club has ever sold? It's a topic that has captured the interest of many football fans and industry insiders alike, and I'm sure it would be intriguing to learn more about the financial dealings that have taken place at this prestigious club. So, do you have any idea who holds the record for the most expensive player ever sold by Arsenal?