imo its the price u put on ur head.
cheap wont save u in a big accident or a fire, a proper auto racing helmet will protect u more and if theres a fire.
i my self have a Bell GTX, i bought it when i 1st started out going to the circuit and still use it to this day in super lap.
even if your not going to go that far into the sport and just do small club sprints i think its still advisable to buy some thing a little more protective for your head.