Have been looking around for these for my son and have found a good deal at toys r us.
It's currently down to £6.98 which is half price from them.
It's currently £15.89 on play.com!!
It's available online (but you have to pay delivery) but you can also get it for this price instore :)
Light and sound version of Ben 10's Omnitrix F/X watch from the popular TV show. Dial up 10 aliens and press the button to activate cool sound effects, it's the ultimate Ben 10 role play experience!
Featuring flashing red and green lights and transformation sound effects taken directly from the TV series, the Omnitrix F/X provides the ultimate role play experience! Like Ben's watch, the Omnitrix F/X will signal activation and de-activation with cool lights and sound effects. The alien's silhouettes can be seen on the face of the watch and are backlit for an easier view. Turn the dial and select an alien! Turn the dial then press the button to activate cool sound effects from the TV show!