I have no idea what prices in India are like. About how much should it cost me to take a taxi from New Delhi Int'l airport to the 'Cyber City' (a.k.a. 'DLF Phase 3')? The distance is about 5 km.
Taxi fares in most Indian cities are regulated by the government.
According to the Delhi Traffic Police, taxis in Delhi are supposed to cost:
Rs 25/- for first Kilometer [sic] (upon downing the meter) and thereafter Rs. 14.00/- per Kilometer for Non-AC taxis and Rs . 16.00/ per Kilometer for AC taxis for every additional Kilometer
Night Charges: 25% of the fare (11:00 PM to 5:00 AM)
Waiting Charges: Rs 30/- per hour or part thereof (Subject to a minimum of 15 minutes stay)
Luggage: Rs. 10/- shall be charged as extra luggage charges whereas the driver/operator shall not charge and [sic] money for a shopping bag or a small suitcase
This means that in the daytime, five kilometers in an air-conditioned taxi should generally cost less than INR 130.
By the way, is the reason you want to know this to avoid getting cheated on the price?
In that case, consider getting a prepaid taxi from one of the counters near the arrivals hall at the airport. There is no bargaining there, they take the same rates from everyone, and you won't get cheated. In this case, you're not supposed to pay anything directly to the driver, and there's no need to tip either.
Your alternative is going outside the airport and finding a (hopefully metered) taxi there. But you never know whether the meter has been tampered with, and you never know what sort of driver you get. So, there are many good reasons to get a prepaid taxi. It may end up costing you slighty more than a normal taxi (assuming the latter has a functional, non-tampered meter), but it may also save you a lot of potential hassle.