But like everything else, it is about value of the thing I'm buying, too. I also put a high price on quiet helmets. I find that even with earplugs, there's little more valuable equipment on every ride than a quiet helmet. I do not get as fatigued, which means I am safer when the background noise is less.
So, I buy the quietest helmet I can afford that also has the DOT and Snell ratings on them.