Due to a computer error, El-Al accidently sold flights from New-York to Israel for $400 (normally $1200-1600). What should the 5000 people who bought tickets at the low rate do?
Rabbi Yair Hoffman
In the United States itself, domestic carriers are not allowed to have these two separate fees, but international carriers are allowed to do so It is this author’s view, the fact that it is technically not part of the sale itself, has implications both ways too – and one would not be forced to undo the deal from a halachic perspective....
Is there an obligation of going beyond the letter of the law here and return it anyway?
It is this author’s opinion it is recommended that one go beyond the letter of the law when there are individuals who would undergo financial distress in such circumstances. Here, however, each individual should make the choice himself.
I hate these kinds of answers. Firstly - you don't really understand what the final decision is. Would El-Al - a large company - enter financial distress in these circumstances? Secondly, how much Torah learning do you need to figure out you are not supposed to abuse someone's honest mistake? (funnily enough, he actually reached the opposite answer).
Moment Magazine asked Randy Cohen, the former New York Times Ethicist and author of the new book Be Good: How to Navigate The Ethics of Everything.
El Al should offer to honor all those tickets, and the customers should decline the offer....However, even if El Al offers to make good on the tickets, we are not supposed to exploit someone. If you see someone’s wallet on the ground you are supposed to return it, not keep it
I recommend you read the entire answer. It is clear, concise and does not go into needless Pilpul to state the obvious answer, that you shouldn't be profiting from someone's honest mistake.