What would be the price for a ticket from London to Paris by train?

As an AI language model, I don't have real-time access to pricing information, and train ticket prices can vary based on factors such as the specific route, travel date, time of day, and type of ticket (e.g., standard, first class, advance purchase, etc.).

However, to give you a general idea of the cost, here are approximate price ranges for one-way train tickets from London to Paris:

- Standard Class (Off-Peak): Approximately £50 to £75

- Standard Class (Peak): Approximately £70 to £100

- First Class (Off-Peak): Approximately £100 to £150

- First Class (Peak): Approximately £125 to £180

It's important to note that these prices are just rough estimates and may vary depending on the specific train service and booking platform. To obtain the most up-to-date and accurate pricing information, I recommend checking with a reputable train operator or booking website, such as Eurostar, Trainline, or Thetrainline.com.