book Shenzhen Taxi in advance?

Hi,

My boss will arrive at bao'an airport in a couple of days and I wonder if it’s possible to book a cab in advance?
He has been there one time before and took a cab from the airport and got to pay a huge amount of money to get to his hotel, when he later took a cab back he got to pay much less…therefor he knew he had been fooled….so trying to avoid that to happened again.
Or what is your best advice?

Thanks in advance for your answer!