First up, please no arguments on the pro's and con's of helmet wearing 'cos i'm NOT interested. 
What I am interested in however is a recommendation of a fairly cheap helmet. My specifications are as follows;
Fairly small & lightweight
Breathable (so lots or air vents?)
Must be able to fit my helmet mounted EL-450 light on it.
I don't want to spend more than £30-£40 on one.
I currenly have a cheapo challenge helmet that I got from Argos when I first started cycling and I've busted the strap on it already, and it is a tad on the bulky side.
TIA

What I am interested in however is a recommendation of a fairly cheap helmet. My specifications are as follows;
Fairly small & lightweight
Breathable (so lots or air vents?)
Must be able to fit my helmet mounted EL-450 light on it.
I don't want to spend more than £30-£40 on one.
I currenly have a cheapo challenge helmet that I got from Argos when I first started cycling and I've busted the strap on it already, and it is a tad on the bulky side.
TIA