About why I'd estimate a higher price. The material (100% Vicuna) and the designer (Valentino) would lead me to believe it's worth more. Also, while taking measurements earlier I flipped the label over an found the price tag. I have attached the image of the price tag of $7,500.
Here are the measurements I just took of the jacket.
Chest pit to pit: 22.5"
Shoulder 18.5" across
Sleeve shoulder to middle end point of cuff 23.5"