You may go to the Daihu Lu Bus Station to take a bus to get to the Mt. Sanqing. As I know, there are two buses in a day. One leaves at 07:50 and the other leaves at 12:50. The trip needs around 2 hours. If you have 3 or 4 persons, I think taxi would be more favorable. The cost from the downtown of Shangrao to the mountain is around CNY200. It’s economical for you four to share the cost.