It's back to what a consumer thinks is better for them, and in most cases it's all about marketing and sales. On the weekend, I overheard a sales guy at one of my LBS answer a customer who just bought a new bike for her daughter about a bike helmets for the daughter. He said something to the effect of - "well, the cheaper one is like your basic helmet and will protect her head. But the more expensive one has better materials and will be MUCH SAFER for her in the long run!!!!".

After they left that section of the store, I checked out the two helmets - the cheapest one was around $19 and the one the lady wound up buying for her daughter cost just over $120. So at least the store punched in an extra $100 on that sale.