Yep! I check mine before I even leave the store. And have found mistakes. Grocery stores are the worst for that. An item is on sale and you buy it for that reason, then while busy unloading your cart it rings through without you watching at the usually inflated price. I've caught one Grocery Store three times in a row. Finally had a little chat with the manager about it.

Good heads up there.... we all need to save money.