I saved $42.90 today just by checking my receipts!
Went to a surf shop to get Wes some new shorts for summer, one "good" pair and a few wear anywhere pairs. If you have a teenager you will know that brand clothing is not cheap, hell it's not even good value for your money, it is an unadulterated rip off. That said I got the shorts 50% off so now they were only a slight rip off. I paid and checked my receipt and found they had charged me twice for a $40 pair, so I got that back in a flash. They were apologetic but I am glad I checked.
Second receipt was from Coles. I had to do my groceries and they had some 1L milk reduced to 95c, the first one went through ok but the second came up as $2.89. I didnt notice as I was still packing the stuff onto the checkout but I did check before I walked away. They refunded the $2.90 and gave me the milk for free - Cheering!!
It certainly pays to check. Last fortnight Dave spied our checkout operator putting our apples through at $4.29 per kg instead of $2.99, she just didn't know what type of apples they were and had had a guess! Makes you wonder how many times it happens when you DONT catch it.