It is very common in this part of the world to agree on a price before you actually step into the taxi (i.e haggle). Of course, if your hotel arranges a taxi for you, then the price is most likely already set (?). I am not really sure what the "base" price is, but when I took a taxi from CAI airport to my hotel back in January, I made sure I "negotiated" a price with the cab driver before I got in.