If one purchases an item in a store and sees as the clerk is entering the price of the item in the computer and it is the wrong price (as in cheaper for this dilemma) is it halachically necessary to tell them about the mistake or to think it is a gift from heaven for a cheaper price and say nothing.
I learned something along the lines that is is not always required to notify an error during a study session. But maybe it was after the fact and not during the fact? If it is a Kiddush Hashem it is always necessary to tell them but what if it were a small item and the clerk may think of you as foolish or crazy (perhaps righteous) to tell them about it?
This is talking about a non-Jewish owned business and most likely a corporation that is large like a major super-market chain.
If the item were expensive maybe that would be another story altogether?