No...well, I recommended that you do.
My wife does and some times she finds a small error.
The most common error being when a promotional offer (i.e. buy one / get one second at half price, 25% off, etc) does not get deducted.
She reckons that without a little diligence she could miss-out on around 50p - £1 per month. That equates to up to about £12 per year. Multiply this by every shopper in the UK and it quickly builds-up to around a whopping £1/4 billion a year.
That is not great, but it is how some supermarkets handle it that really irritates her.
She is told to take her receipt and wait in the (so called) customer service queue - behind customers buying lottery tickets, etc - to claim her money back.
This is not good enough.
If I were running a supermarket I would would take this as an opportunity to deliver a brand experience that aims to surprise and delight the consumer.
Make a bigger deal of it. The check-out person should be empowered to thank the consumer for highlighting the error, and maybe even rewarding them (In some supermarkets not long ago the policy was to pay-out double the difference.)
Okay, I recognise that this could reduce revenues and add costs (clearly not a great combination). However, turning this situation into a positive and memorable brand experience would build greater loyalty and advocacy.
A good way to differentiate and win greater market share in this extremely competitive market.