This morning, four of us, two couples, are traveling from Plymouth, England to London Heathrow airport. My original plan had been to take a taxi to the train station and then the train to Heathrow. This would have involved a change at Paddington station to the Heathrow Express. The cost would have been 328 GBP plus the taxi fare to the train station in Plymouth. One of my more frugal traveling companions found that we could take a taxi directly from our hotel In Plymouth to the front door of the Sofitel at Heathrow for $280 GBP. Cheaper and infinitely less hassle!
We realized that a taxi might be an option when we explored Southern Devon by taxi. When split 4 or 6 ways a taxi fare becomes quite reasonable.