If you want a small 'be seen' front flashing light then as you said they seem to be hard to buy on their own.
This set of front and rear 1/2 watt blinky's is good value though:http://www.ebay.co.uk/itm/Raleigh-Front ... 20b9fb6a6ahttp://www.ebay.co.uk/itm/Raleigh-RX-2- ... 20d687c717
I've got similar 1/2 watt front and rears that i've bought over the years and they are good and bright in terms of being seen.
The History Man wrote:
This is for twilight and beyond on unlit country lanes and B roads.
This kind of contradicts your original requirement and implies that maybe you want a light to see where you going?
If thats the case then this is a good value set:http://www.tredz.co.uk/.Smart-Lunar-35- ... tAodZTgA1Q
Near enough the same rear light as the other two ebay links but with a proper front light that also has a flashing mode. Direct from china sets aside I think for £24 its hard to beat. The front light is pretty bright, alot brighter than those cheapo coloured bezel chinese things (which are not 270 lumens as advertised, more like 50).