it's true that taking taxi at night time is more expensive than daytime.it will take you about 1 hours to go to the destination.

Yes, taxi fare has surcharge at night from 23:00 to 05:00 the next morning. It is CNY16 for the first three kilometers, an additional charge of CNY3.1 for every succeeding kilometer within 10 kilometers and CNY4.1 for every succeeding kilometer after 10 kilometers. You can bargain over prices when taking taxis at night.
It takes about one hour by taxi from the airport to your hotel and the taxi fare at night may be around CNY200.
I think you can take the airport night line from the airport to People's Square. Then walk about 10 minutes towards west to the hotel.