How long would a trip from Xi'an to Huashan summit and back take/cost? Is it possible in one day?

It is possible to finish visiting in one day, but it is suggested to go there in the afternoon and climb the mountain at night. Then you can go back to Xian the next day morning.
The bus fare is around 22RMB. If you want to go there in the afternoon, you may need to take the buellet train and the fare is around 35RMB for the second class seat and 60RMB for the first class seat.

Thanks!