I'd pay this much for a coat from M&S if I thought that it was stylish and if the fabric was good. I'd also pay a premium for British manufacture.
It's Karen Millen/Jigsaw/Reiss prices. This particular coat is OK but not really my style. However, I wouldn't balk at paying top end high street prices for something from M&S. The Autograph range started out at this sort of price point when it launched, and the clothes were good. It's gone downhill since. I'm pleased to see M&S trying to up their game a bit with a premium collection.