My alarm clock is also paid 4 radio-controlled, so I guess it is not the function that justifies the price.
Note that as well as low noise, this is NOT silent Clock Setting. The second hand is a second hand which marks the seconds (unlike quieter versions that run continuously), and in a quiet room, it is heard. Do not put either in the room, so.
[Updated at 6 months]: I withdraw a star because after 6 months of using the second hand stopped spinning. The mechanism of this clock at 30 euros is the low-end flush with the floor.