Sainsbury's has become our cheapest retailer after weeks of striving to match the prices of its nearest rivals. It's the luck of the draw as to whether we choose items the retailer has put on special offer - this was evidently Sainsbury's week. Its £49.19 basket was helped by the half-price Kleenex for Men tissues, on offer at £1.59. Its Birds Eye Chicken Dippers were also half price at £1.34, despite being 238g bigger than at the other retailers. Unfortunately for Asda, Jacob's Creek Chardonnay replaced Hardys Shiraz Cabernet Sauvignon on our list this week - and it has gone up £1.97 since last week. This boosted the price of its basket to £49.69 in total. Asda's apples were also 30p more expensive. It did, however, provide the cheapest Mars Celebrations and Hovis white loaf. Tesco's £50.14 basket was also hit by an increase in the price of Jacob's Creek Chardonnay, which was £2 more than last week. However, McCain Smiles fell in price from £1.09 to 78p. Tesco also offered larger bags of Haribo Starmix, which were on buy-one-get-one-free. Last week's runner up, Morrisons, is this week's fourth-cheapest retailer with a £50.33 basket. Its prices were almost neck and neck with Asda and Sainsbury's, but its Old El Paso Dinner Kit, which went up in price from £1.86 to £2.09, denied it third position. The jostle to avoid the ignominy of most expensive retailer has swung in favour of Waitrose this week. Its £56.72 basket was more expensive than most beause of its steeply priced own-label foods such as Scotch eggs and quiche lorraine. Its loose apples were more than three times the price of most. Somerfield was once again most expensive with a £57.12 basket. It can't have expected anyone to fancy the Old El Paso Dinner Kit as the price was up 99p from last week. The retailer's Birds Eye Chicken Dippers were also 60p more than those at Asda, Morrisons and Tesco.