I only Use now KN95 mask because compared to N95 of US standard it is too expensive while kn95 is 300% lower in price.
I bought KN95 as I've heard it's a good mask but after receiving the actual mask, I've seen that there's an allowance in the middle of it.
I went back to surgical mask, it's also cheap and I've bought a box I guess around $4 for 50 pcs. I can't remember.