The iPhone 15 costs £590.00 new compared with £79.00 refurbished (no longer sold new) for the iPhone XS. Buying the iPhone 15 refurbished instead of new saves £291.00. If you want 5G, USB-C charging and a larger 6.1" screen, the iPhone 15 is the better choice. If value is your priority, the iPhone XS offers the stronger buy at a lower price point.