Apologies first of all. The original mask in real world leather and calli glass should be 188 GP. Apparently a 6 wanted to jump in there.

If you are looking for something that also covers the back of the head I can offer you:

With the straps, but stronger: 250 GP, which is made with calli glass and magim beast hide (teir 2 material).
With a coif/arming cap addition: 375 GP, made from magim beast hide and the calli glass.