The helmet for the nobility is not necessarily distinguished by the presence of gold. Often the difference between a simple and expensive helmet lies in the field of assembly technology and design.
A simple example: the cuirass is expensive and pristizhnom armor inaccessible to simple infantrymen, the brigantine is cheap and accessible to all.
Helmets of elite warriors - they can not be many. And they should belong only to the commanders of the detachments.
Expensive technologies: a seamless dome or a dome with hidden seams, curved ribs, anatomical elements (half-masks and full masks), ornamentation and gilding, individual elements on the top of the helmet. You can not just take off the gilding and call it a simple helmet.
https://forum.kingdomcomerpg.com/uploads/default/optimized/3X/0/3/030e420270c4dec36d5945c459acf657ea861b4a_1_690x493.jpg
https://forum.kingdomcomerpg.com/uploads/default/optimized/3X/c/0/c03c7dec164199558b59c96359c41712924a2931_1_690x383.jpg
https://forum.kingdomcomerpg.com/uploads/default/optimized/3X/5/b/5b6f7b12fc45bfa84b0223f13212945ea88a1966_1_690x387.jpg
http://swordmaster.org/uploads/posts/2016-02/1454505251_shelom01.jpg
More simple helmets are made easier and not so exquisite.
The simplest helmets for ordinary soldiers.
I hope the visual difference is visible right away. If not - then I’m helpless.