Lidl will have these motion sensors instore in various colours from Monday 27/01/14 for £3.99 which seems great value, you get a 3 year warranty included too.
Product information :-
Suitable for in- and outdoor halogen, energy-saving and LED bulbs
12m detection range and 180° detection angle with adjustable lighting time from 10 seconds to 7 minutes
Nominal max. load:
- Halogen bulbs: 1200W
- Energy-saving bulbs: 300W
3 year manufacturer's warranty