If a week&;s trip to Tibet includes round-trip transportation time, it is relatively short. I suggest that you choose to fly back and forth, and the cost may be higher, but you can have more time to play in Tibet. Moreover, air tickets are not necessarily more expensive than trains, and air tickets to and from Tibet in some areas are cheaper than hard sleeper trains. A round-trip flight in Tibet costs about 2500 yuan, depending on where and when you leave.