@tsarstepan,
It should be OK to use valved masks (which are preferable anyway).
The valve makes them useless for use on sick people. The germs would just escape through the valve.
Although if someone doesn't have a supply of masks already, they are out of luck regardless of what kind they want. Everyone is going to be sold out at this point.
Bulk grocery shopping within reason isn't too bad of an idea either. If someone can limit their trips to the grocery store to once every other week, that reduces their exposure to other people.