Why the typical alarmist BF style yell at clouds intro of "$350 helmet for TdF riders" ?
You can get a mips Giro road helmet for $55 all day long. You can get a mips helmet around $60 that's a decent lid from most any big name brand all the time.
The $350 helmets you often see have mips, a wireless crash sensor to communicate to your GPS or an app on your phone, and also are likely a super aero racing shape. If you don't need all that.......why get it?
Why all the hand waving? If racing is your hobby and you have cash........buy what you want. If it isn't, still buy what you want.