So I guess it's good to look for freebees caused by the mistakes of the people that work for these greedy corporations. Yes, they are in business to make money. And when the corporation decides they will just let some worker go, to make up for the lost sales, that's fine.
To me, if the cost of a product on only a few cents off, I let it go. If it's more, I bring it to the cashier's attention to get the correct price, and nobody lose. For every cause, there is an effect.