Organizations that really need it probably aren't going to be buying from a sketchy Amazon marketplace seller.
I'd say the good version of this would be buying up hand sanitizer in January, selling it for markup yesterday.
And if somebody is mad that you're making money, tell people a certain percentage of the profits goes to charity.
Vast majority of hoarders don't hoard nearly that much.
Vast majority of hoarders don't plan on exploiting people.