If you are a business operator, be responsible of your action. Never cheat your customers. They have a high regard on you as the owner. One bad action to them would mean regret. It is simply because they will transfer to a business that is dealing with them with honesty. One cheat you may do is the sudden change of pricing . They will get shock because it was not found in the tagging. They will only know the increase once they are in the cashiering counter to pay their purchases. Please never do this if you run a business like a grocery store.