10 for $10
But this post, asking why you'd want to buy 10 half-gallons of milk for $10, reminds me of something I've observed:
Supermarkets here do often have Buy X for $Y promotions (see for example this week's local Albertsons flier); and they often are for large amounts of stuff. But here's the thing: they're all just flimflam. Check the small print on the shelf tag, and you always find a unit price of $Y/X: if milk's 10 for £10, you can buy 1 for $1.
This seems different to the UK, where on similar offers you do need to buy the full quantity to get the discount. It makes me wonder (as I have before on other differences) if there's some legal requirement here: maybe you must be able to buy one unit at the offer price?