Higher priced helmets are often perceived as being about brand names or race graphics or better features. The reality of it is that while higher priced helmets offer those benefits they are also usually lighter and more aerodynamic and fit better than cheaper helmets. Lighter overall weight results in a rider having less neck fatigue over the length of a ride. Theoretically this makes him a safer rider because he’s less tired. He would also, theoretically ride longer and more often, thus improving his riding skills.
Aerodynamics play a role not only in ventilating the helmet and keeping the rider’s head cooler and more comfortable, but improved aerodynamics also make the helmet cut through the wind more effectively, further creating less fatigue through buffeting the head or lift from air coming up under the helmet at speed. For years Shoei helmet riders at Daytona would claim the aerodynamic qualities of their helmets provided them almost 2mph on the back straight, all other things being equal, this mainly due to a lack of lift and through more effective aerodynamics. So developing a helmet thoroughly in a wind tunnel (vs. just “testing” it after it’s made,) makes for a better, more safe helmet. Although is development takes time and money
Helmet fit is more complicated than most think because most dealers are not well trained to fit a helmet properly and most buyers don’t wear a helmet long enough in a store before buying it to determine proper fit. This results in many people buying a helmet that is too loose (or too big) to be really effective in a crash. Fit has to be optimized through both the relationship of the shell to the EPS liner to the comfort liner. Another common issue are people who know they are a “large” in one model and assume they will be a large in any model. Which can sometimes not be the case because of the number of shell sizes. The shell being the hard outer layer of the helmet.
More expensive helmets usually cover their full size range (XXS to XXL or larger) with more shell sizes (sometimes as many as 3-5 shell sizes to cover the size range) where cheaper helmets cover a size range with only two size shells, making up the range with EPS liners and alot more foam. This results in more movement of the helmet on the head at speed than necessary because there is more soft padding than usual in some helmets. The increased number of shells in a helmet model adds greatly to the price you have to charge for the helmet.
Yes, you get what you pay for. In expensive helmets you are paying most for fit and comfort and ventilation through aerodynamics and lighter weight. Which have an indirect, yet still important bearing on safety- the comfort and fatigue level of the rider wearing it.