To use an absurdly simplified example, imagine if access to sanitizer reduces effective reproduction number (Re) of the virus, in a way proportional to the amount of people that have this access. Every day the virus spreads, the probability of an individual getting infected grows, so the need to have the sanitizer grows as well.
When that sanitizer is most needed is at the very, very beginning - where it could halt a pandemic in its tracks. But the "maximum need" as perceived by the hoarders will occur only at the point the pandemic is about to burn itself out anyway. Which is precisely when it'll do the least good. A savvy hoarder will sell then, and make a hefty profit. A less savvy hoarder will mistime that point, sell late, and make a smaller profit.
To me, this is the best argument against price gauging.
That said, I think it still doesn't matter because
1) You can substitute hand sanitizer with soap. In a way, hand sanitizer is a luxury item.
2) There is no monopoly on hand sanitizer. There are always less-savvy hoarders who sell their products so manufacturing the pandemic by hoarding doesn't work
3) Preventing the early spread of the virus requires state-level coordination to be successful or else the virus spreads anyway. So for the low reproduction number scenario, let's assume massive state intervention. In that case, containment is very likely and there is no future excessive demand for hand sanitizer, thus even savvy hoarders will sell their stock early on.
To use an absurdly simplified example, imagine if access to sanitizer reduces effective reproduction number (Re) of the virus, in a way proportional to the amount of people that have this access. Every day the virus spreads, the probability of an individual getting infected grows, so the need to have the sanitizer grows as well.
When that sanitizer is most needed is at the very, very beginning - where it could halt a pandemic in its tracks. But the "maximum need" as perceived by the hoarders will occur only at the point the pandemic is about to burn itself out anyway. Which is precisely when it'll do the least good. A savvy hoarder will sell then, and make a hefty profit. A less savvy hoarder will mistime that point, sell late, and make a smaller profit.