It has been my experience that everyone seems to have the same prices in China. TA's, online agents, airline booking counters, etc. There seems to be an amount of seats for each discount level of fare and everyone has acces to it. Once the discount is gone from one site or location it is gone from the others too. I have tried checking several different sources before and always have been given the same price. This is despite the fact that here in China there are always people on the street handing out cards with different booking agents numbers and advertising great discount rates. When calling them though they never seem to have a better discount than everyone else. This has been my experience, so I suggest just booking tickets online.