Manolo Blahnik black high heel sling back shoes

These are Manolo Blahnik Marca shoes in like-new condition. Worn a couple of times only. Size 40 equivalent to 9 M. Black glossy patent leather upper, leather soles. Still in their original box. Purchased new for $675. Included is a cotton draw string carry bag. Size is 40 EU. And this site suggests this is equivalent to a 9.5-10US. I can tell you that these shoes fit more like a 8.5-9US