If you like travelling around Tibet during the day time and clubbing in the night time, Asia Hotel would be your best option. It's near the two biggest bars and the Jokhang Temple, very close. Double rooms only costs 50 yuan per day in june and july, multiple-room is about 20 yuan a bed. By the way there are many chairs in the middle of the courtyard , bask in the sun can be very uncomfortable to read books. There are too many foreign backpackers living in here. You can get Longer hot water supporting, stuffs storage without money, and more intimate services. Unfortunately, these guys are not providing washing clothes for free.
Snow hotel is as well good choice, as long as 30 yuan a bed here, but the bed is relatively large, clean and comfortable living which was also a lot of foreigners, the hotel's restaurant environment is also good.