As far as a $200 helmet vs. a $700 Shoei or Arai is concerned, lets just say that like most things, you get what you pay for. Are they safer? They're industry leaders and have much more R&D and testing than pretty much anyone else, so probably. They exceed the certification testing standards. Do they have more bells and whistles? If you mean tech like bluetooth, than not necessarily, but if you mean things like aerodynamics, comfort, quietness, airflow venting, and other things that actually make a difference to track riders, then yes they do.
Really it's like any other piece of sports equipment. I remember when I first started getting into hockey in college and I got a pair of used Bauer skates from Play It Again. They were lower level skates and being used, had been broken into someone else's feet, so they hurt my feet and I had a tough time skating in them. Then I got a new pair of mid level Bauers and it was a nice improvement, but they still didn't feel right. A couple of years went by and I finally bit the bullet and got a pair of Mission Flyweights on a season end closeout. Even on sale they were more than double what the Bauers were, but the difference was night and day. They fit like slippers and became an extension of my feet instead of blocks that I had to fight to get to do what I wanted.
I find it funny that someone who's never used a high end helmet is scoffing at the price tag. As the saying goes, if you have a $100 head, buy a $100 helmet. As for me, I'll spend a little extra to make sure I'm not getting a bargain basement reject. There's a reason helmet's go on sale for rock bottom prices. The foam in cheaper helmets breaks down faster than in higher end helmets, and when they go on sale, that means they've sat around for a long time, reducing the time the helmet should be used. You can pay $100 every two years on a helmet if you want (to make sure the foam is up to snuff), but I'd rather spend $500 on a better helmet and keep it for five years. My head is worth it. Is yours?