Originally Posted by
indyfabz
No, as long as it fits you properly and you wear it properly.
^^^ This, and if the helmet meets whatever safety standard is applicable to your region, e.g. EN 1078 in the EU.
It's much like motorcycle helmets: all helmets, regardless of price, must meet the same safety standards - so poor people get the same level of safety protection as rich people.
You pay extra for better padding, vision, fit, ventilation, lighter weight, color, shape, etc. How those factors affect "safety" is debatable; what should not be debatable is a standard level of impact protection (g-forces transmitted to the head in the event of an impact), which should be controlled with the relevant safety standard.