How, pray tell?
Limit per customer, like they have on some sale items.
The only reason they would limit someone’s purchase would be out of the goodness of their heart
In states without a law preventing it, the only motivation for a store not to price gouge would be because it’s bad PR. Similarly, it would be good PR to limit the amount per customer, to look like good citizens.
If I recall correctly they set limits on gas purchases by Sandy but by the time they got around to setting the limits most gas stations had run out. The only way setting limits would be good PR is if they paid to advertise it as such. Otherwise social media would be full of “What the ***??? I went to fill up my tank and the attendant was just like ‘sorry, 5 gallons per customer’. I am never shopping at XXXX again”