Always, always, check. I can't understand why people refuse to take their docket. The number of errors I've found over the years is enormous and the amount I have saved accordingly is well worth the effort of checking the price of every item - usually about one overcharge per week, at least receiving the difference between the correct price and the overcharge, often resulting in a total refund and a freebie. I strongly object to the store practice of asking if the customer wants the receipt. Issue, not discard, should be routine.

I take my dockets on everything I spend from all suppliers. I keep track in a spreadsheet, recording every cent spent. It helps to recognise wasteful spending. 

Yes, there have been a few errors and most are picked up at the time. We are creatures of habit and mostly buy the same items every time. the cost is pretty much known in advance and by shopping to a list, I have a fair idea how much I'm spending.

Dockets issued my Woolworth's Mowbray (Tas) store can't be read as the ink is really faded. Same for the Scottsdale store. Difficulty reading even with a magnifying glass. I guess it's the economy of not replacing ink cartridges, or printing on grey scale.

I'm a confirmed "specials" chaser and have a good memory for price figures. I also use Foodland pensioner discounts and Flybuys/Everyday Rewards points to save what I can. My wife gets a bit stroppy with me when I tell her: "Don't buy that this week, it'll be cheaper in the next specials brochure" or "That was only $xx last week!"

Bill, I've known many specials "chasers" in my lifetime. I don't bother. Never have. These days, my closest Woolies is 30km distant (60km return) and closest IGA is 12km distant (24 ret). Petrol this week was $1.44 ltr and I would use 6 litres for a Woolies shop. 

I have always considered the costs incurred in chasing specials. It seems to me not many people do. 

Guess I'm lucky, ArJay. Foodland is 700 metres away, Coles and Woolies are about two Kms up the road. So I do quite well out of weekly discounts and points which provide $10 off every couple of weeks.

Check all my dockets in every shop I go into without fail for this very reason.  Only been overcharged once in the last few years.  Not convinced that mistakes are as common as people make out - or else I am just lucky and supermarkets and other stores know not to mess with me as I will make a fuss as many have learnt to their cost.  It drives my partner mad when I stand at the register and check every item before we leave the store.  But if you stand there and check immediately, in their presence, they cannot argue with you about it, like they do when you walk away and check it later.

With automation, mistakes have become a lot less frequent.  Who remembers the old days with manual cash registers etc?  Continual mistakes in those days.  My mother had endless arguments about register mistakes and overcharging.  Now also less problems with incorrect change with the register telling the cashier how much change to give etc.  Given the lack of basic arithmetical skills these days, we'd have no hope.

I nearly forgot - petrol discounts of 4c per litre are worth having too.

I use the calculator on my phone as I go round the supermarket. I weigh all loose fruit and veg and work out the price and add that to the calculator. When I get to the checkout, I can easily check whether the bill is the same as my calculator. It usually is, although there may be a few cents difference that is easily explained by the overestimation of the cost of the loose fruit and veg. On the very rare occasions when an item shows a different price at the checkout than on the shelf, there has never been any issue with the supermarket rectifying the error.

ArJay, I totally disagree with you. You are losing a lot of cash over a year. With $10 off per 2,000 points through Coles and Woolies (and buying specials when needed), I save $20 every other month. I don't enter into other spurious schemes, except for Nielsen Net Ratings on the computer which gives me another $10 voucher every month or so. Then there's Foodland's weekly pensioner discount of 5% off each shop on Wednesday or Thursday. I only buy petrol at the bottom of the price cycle, $1.21.9 this past week ($1.17.9 to me). I run two cars - one only occasionally on historic club events. The saving at the bottom of the docket is quite gratifying.

I disagree with Celia's comment re dirty fuel. Suppliers are very careful these days as cleaning tanks is an expensive business. A tip - turn off your engine while waiting in the queue. The savings are genuine, even if factored into grocery prices.

Don't forget that 2,000 points includes petrol purchases as well as groceries plus the odd bonus issue often numbering in the hundreds. Coles are better than Woolies for those and liquor purchases are also included.

As for fuel discounts, I don't see the relevance to distance travelled - 4c off per litre is still 4c off regardless of distance and is a saving on usage whether large or small.