Arguably, 3M should have put the price up as soon as demand shot up, so that stock would not run out. Shortages are a market inefficiency. If masks are suddenly valuable because they are required to handle an ongoing health crisis, the price ought to reflect that. The "price gougers" are correcting that inefficiency, and the profit that they make is their comission.

The trouble is that unlike in the perfect world we wish the market worked in, the most deserving are not always the best funded. So it would probably be more ethical for either 3M or the "price gougers" to offer some sort of preferential pricing - although deciding who to offer it to might be tricky.

Perhaps, in an ideal world, the government is competently in charge of any urgent social emergency, and if resources are required the government can pluck them out of any incipient market bubble by gently requiring that the entire stock be sold to them, at a fair market price.