Last year I bought a Bushnell Radar gun. It was somewhere around $70 and I think it's the one in the link below. Not mentioned was it's ability to display either kph or mph, but it does do both. One word of caution, it's best to let someone use it who is NOT holding the transmitter.

http://www.amazon.com/Bushnell-CBV00...6576995&sr=8-1

There's another one on Amazon for only $70 as well. Not sure what the difference is.