I regularly take taxis between Norwich Airport and the train station (more than 1.5 miles away) and have never paid more than £20 - usually around £15 for journeys from the station (where I have asked the driver to drop me off at McDonalds down the road to avoid the airport's drop-off fee), slightly more for journeys originating at the airport where the fee can't be avoided.
At the station I grab a cab off the rank. At the airport I prebook through the airport.
I really don't know where the OP's figures come from. Clearly a rip-off, well in excess of the going rate.