If you’re a serious skincare addict like Camilla and I then you probably already know about Estée Lauder’s Advanced Night Repair, which has long been a favourite of beauty editors the world over. It’s known for being the best anti-ageing serum on the market, and it has 30 years’ worth of dedicated fans who will testify that it really does leave skin looking smoother, younger and more radiant. The problem is that, like many high-end serums, it’s extremely expensive. I would argue that although it’s pricey, it’s still great value for money because a bottle lasts forever and the product…