The only difference of any importance I have found in helmets is the fit. My favorite helmet that I spent $90 (sale from $130) is the most comfortable one I have ever worn. I was tired of crappy fitting $30-$40 helmets. I have found the nape gripping mechanisms to be shoddy, and the padding to be cheap and flimsy. That is the only reason I paid that much for the helmet, it felt far and stayed in place better than any of the 15 others I tried on. The parts that make it do this add maybe $3 to the cost. I don't really care about the styling or color.
On the other hand, I only wear a helmet about 50% of the time. But when I choose to wear one, I want it to be comfortable. I neither have nor want a kit. It is very hard to find highly comfortable race type wear that is devoid of advertisement.