200$ helmets are usually full faced. That should be a self explained advantage.

Expensive roadie helmets may be more aerodynamic but since I don't care about pure speed in that capacity I don't do the research

Cheap helmets usually have less whole / ventilation which is a big thing to some people. Style too. I find cheaper helmets 'generally' make people look very phalyc.

As for protection. Not a diff, they are all standard.