As of January 2016, well-reviewed atomic clocks range in price from $40 to over $100. Simpler models are on the lower end, while models with other features, such as the weather, are higher in the price range.
Atomic clocks are available in a variety of models, from simple round analog faces to more complex kitchen timers with dates.
Atomic clocks use an electronic transition frequency to keep their timekeeping elements accurate. They keep time for mobile phones, GPS and other times when time accuracy is critical.
The idea of the atomic clock was first suggested by Lord Kelvin in 1879. However, the first accurate atomic clock was not built until 1955 by Louis Essen and Jack Parry.