Just bought some coffee beans from Asda and took advantage of their 3 for £5 (or 2 for £4) deal.
When I got home I noticed that the discount given was higher - I paid £3.74 for the three packs.
Checking online, the prices are £2.67 for 1, £3.16 for 2 (£1.58 each)and £3.74 for 3 (£1.25 each).
This scanning error seems to work for all coffees in the deal (inc. Douwe Egberts, Illy, Lavazza, Carte Noir and Asda own brand) but as the starting prices are different the discount varies as well. For instance, 3 packs of Lavazza will cost £3.89 and 3 packs of Douwe Egberts are £4.37).
Don't be greedy online though, if you add six packs to your basket the price seems to revert to the 3 for £5 deal!
3 for £5 deal expires on 22/12/09