I bought two pairs of Tummy Tuck jeans when I was in New York last August, I paid about £40 pair, although the exchange rate has changed since then. They are fab, the most comfortable jeans I have ever worn and no, they don't push the fat up, they just kind of hold everything together but because they're really elastic it's like wearing a comfortable pair of leggings. If I was buying jeans from M&S I would be buying a size 12, the tummy tucks are a US size 4. The only slight problem is that I'm quite short, so had to have them taken up when I came home, but it was well worth it.