Raising the price does not "primarily" cut off the least wealthy potential buyers, that is just one of the effects. Much more important is that it prevents people from hoarding, which is by far the most common result of prices being drastically lower than they ought to be. Leaving the prices low predictably causes shortages, which shut out virtually everyone from purchasing the masks, including the microscopic percentage that wouldn't be able to afford the price increase on an item that usually costs pennies.