I picked this up today in Home Bargains for only £1.99! and thought it may help others, An RAC LED Cycle Safety Set. It said on the shelf the rrp was £6.99 and Amazon are currently selling the identical set for £6.99, it looks a great set for the money.
Contains: 2 LED Safety Lights (Front & Rear),
Cycle Brackets (with intergrated clip for bags etc)
4 'AAA' batteries included.
Also: Static or flash functions
Quick release for security
Can be seen up to 800 metres away
Up to 200 hours of use from a set of batteries.