Let’s throw masks and other PPE onto your list as well.
Ironically the way to make this stuff cheaper would be a three-fold attack.
* Make MORE things that use the same parts, so that making the raw materials is commodity.
* Reduce waste in use (if sterilizing the filters for reuse / etc is possible, etc).
Part 3: Look for alternatives that are feasible.
A hot-zone (book) style line supplied breathing air positive pressure suit that can be scrubbed clean on the outside, OR a similar glove-box (negative draw?, scrubbed inside?) style phone-booth like I think I saw on TV from South Korea (IIRC) would be much better replacements.