Are you being overcharged for groceries? I am overcharged for my groceries half of the time! That is why I now check my receipt before leaving the store instead of when I get home. I buy a lot of thing on sale and often times the store employees have not entered the sale prices into their computers. Another reason is just carelessness on the part of the check-out person.
Not all receipts are trash! Some actually have potential discounts that could help you save on future purchases.
Some stores I go to ask if I want a receipt - the environmentally friendly method would be to say "no", however the thrifty part of me says "yes". I always get a receipt.
Just within this week, I have been overcharged 3 times at 3 different stores! It is important to double check your receipt because accidents can happen.
I just found out that my supermarket has a policy that will give an incorrectly scanned item to you for free. The store will give you a $10 discount on items that are more than $10. Because of this knowledge, I got a $7.99 package of burgers for free.