Originally Posted by DnvrFox
Great question!
I am sure you will get a great diversity of answers, many disagreeing with mine. But, IMHO.
1. Snob appeal and weight - perhaps a few grams difference. Did I say snob appeal?
2. Ventilation - the more expensive have more ventilating openings, and therefore require stronger construction (because of the missing material) to meet ANSI guidelines.
They all have to meet the same safety guidelines.
I use the cheapest that I can find that meets my needs.
+1. Hit it on the head. Giro may be more pricey now because Lance Armstrong wears them. Maybe, maybe not. I find that Giro fits my head better than Bell, but I have both, and they are fine. Paid about $25 each on sale.