Don't know if this will help but here's some information from SNELL's FAQ:

"What's the difference between a $100 Snell certified helmet and a $400 Snell certified Helmet."

-While helmets are primarily a protective device, the true protective capabilities of a helmet, if needed will only come into play for about 2 to 4 milliseconds during the lifetime of the helmet. This leaves a lot of time for that helmet to be doing nothing more than sitting around on a users head. Producing a product that meets the standards is not really very difficult. Producing a helmet that people will buy and wear, and will consistently meet the standards is significantly more difficult. The Snell standards do not measure factors like comfort, ventilation, brand recognition or style, and only indirectly look at fit, weight, materials and workmanship. These are factors that frequently drive helmet cost.

If you want to checkout more of their faq here's the link: SNELL