Depends. If it was Walmart or Amazon hypothetically selling primers, then I'd secretly hope they could be bankrupted by it. Any business that doesnt have billions upon billions in revenue, absolutely notify the owners. Your deal comes at the expense of an actual person. I wont say it is theft, but it is immoral.

PS: I have $80 Kendra tires from a walmart pricing error. Thank you BP? I think thay was you. Yet I even returned CASH dropped onto the ground to customer service (who I know 99% pocketed it). Lead children by example. But nobody gets Karma points for returning mistakes to e.g. the IRS. That is roughly where the majority probably draws this moore.