if you get one dont think it will always tell u that theres a cop all the time. you also have to use some sense and look ahead.
for example i was doin around 80 in a 55 on a open highway with some people behind me doun the same then i noticed a car pullin onto the side of the road about 1/2 a mile ahead n then into some bushes so i slowed down 2 around 65 while the other cars were passin me. the radar detecotor didnt go off until i came real close and then laser went off like 2 times and the cop pulled out and pulled over one of the other cars
i have a bel that retails for around 300 not sure what model but in real good especially kuz it has the letter display instead of just some lights that tell u what kinda of radar it is