Not the first place we would consider for some cool, midcentury design, but Marks & Spencer has it with this Montford armchair.
Don't worry about the red colour, there's a seemingly endless range of fabric options, both plain and patterned to go on that curvy frame, which also also has a sloped back and four tapered wooden legs. The chair is also traditionally sprung and has a reversible seat cushion.
Available to order online in that wide range of fabrics, £549 is the price.