Transfer to downtown Xian on 02/10/2013

Hi I arrive in Xian at 23:50 on 02/10 my flight times have changed I was due in earlier and planned to get the shuttle bus Line 1 to downtown Xian, will I be too late to get this bus now I'm arriving at 23:50. If so how much should I expect to pay for a taxi and are there any available at this time of night. I have contacted a private driver who has quoted 300 RMB to take me to my hotel but I think this is too much. Any advise would be appreciated.