I agree with Rose.
It's hard to figure. In my younger days, I worked in a factory that made spray pumps (like the ones on Windex and such). The materials costs less then a 3 cents per pump. But if you add labor, costs, machines, packaging and all that. The costs per pump went up to roughly 10 cents. Doesn't seem like much, but it really adds up.
I know making a Glock is totally different. But I'm sure they have many of the same things to pay for. My personal guess would be 200-250 per weapon.