Originally Posted by MRT2

A $40 helmet will protect your head as well as a $150 helmet will. Don't think an expensive helmet does anything for noise. Even cheap helmets have plenty of vents. Beyond that, I would take manufacturers claims of superior airflow with a grain of salt. Visors don't do much to protect the eyes. Get protective eye wear. Sunglasses for sunny days, clear lenses for cloudy days, to keep dirt or bugs out of your eyes.

Wear a cycling cap or bandana under your helmet if you think your head might get sunburn through the vents.

A more expensive helmet might get you a better fit, but then again might not. Everybody's head is a little different. Fwiw, I have never paid more than $40 or $50 for a helmet, and have sometimes gotten them on sale for $25 or $30.