Our inventory is inconsistent so we cannot guarantee a certain number of masks or styles. However, for personal requests, it is generally reasonable to ask for 10-15 masks per person. For organizations, 50-75 is pretty reasonable with less room for selection of specific styles.
We may go above this when we are able to, but of course can't make any guarantee!
Masks can be resused! You should dispose of your mask once there is visible damage, the mask no longer fits your face well (headstrap stretched out, damage to the nosewire, etc), or if it becomes difficult to breathe through.