The Stanstead Express is a dedicated train service that operates between London and London Stansted Airport. While the price of a ticket on the Stanstead Express can vary based on several factors such as time of booking, time of travel, and demand, it is generally positioned as a more economical option compared to taxis, especially for solo travelers.

A typical ticket for the Stanstead Express can range from approximately £20 to £30 when booked in advance, while a taxi fare from central London to Stansted can easily exceed £100, depending on traffic and the service provider. However, for groups or travelers with a lot of luggage, taxis may seem more convenient, even if they are costlier.

In summary, while there might be instances where the price of a Stanstead Express ticket can approach that of a taxi (particularly during peak times or last-minute purchases), overall, it tends to be the more affordable option for airport transfers. Nonetheless, the choice between the two will largely depend on personal circumstances like travel time, convenience, and number of passengers.