Not a silly question, an instructive one that you just proved my point. There is investment necessary in infrastructure/tools and education, not to mention actually making a profit for the wage of the person doing the work. That all adds cost beyond materials. Which, by the way, is significant. 1/8" titanium rod grade 5, 6" long, which would roughly be a similar volume for making glasses, is >$7 USD before tax and shipping on McMaster Carr.
You would be surprised at how badly ecosystems can be neglected in the name of progress.