im here at sanlitun(the village and yashow clothing market)area.please help me how to go to greatwall badaling in a very cheaper way,like bus and subway.how to go there and how to go back to my place of origin sanlitun/yashow area?how much will i spend money?is it safe,okay and not risky that i am only alone going to the greatwall badaling?please answer my questions.im waiting to your immediate response.thanks in advance.