You can read more about the collaboration between AMI and Gap for this limited series here: https://gearpatrol.com/2017/09/27/gap-gq-ami-collection/. The GQ article announcing the collection ("the coolest menswear designers on the planet") can be found here: https://www.gq.com/gallery/gq-x-gap-2017-collection-how-to-shop
Measurements (taken while laying flat - keep in mind the material is pretty heavy):
Chest (pit-to-pit): 20.5 inches
Shoulder (seam-to-seam): 19 inches
Sleeve length (outside shoulder to hem): 23 inches
Back length (bottom of collar to hem): 28 inches
Retail price for the coat was $250, but it instantly sold out everywhere and you will generally find them for resale from anywhere between $200-$600 (and finding them in XS and Small sizes is difficult). Here are the original details from Gap's website from 2017:
Designer Alexandre Mattiussi's fresh take on modern French style blurs the lines between sportswear and streetwear.
Soft, twill wool weave.
Dropped shoulders, long sleeves with hidden layer rib-knit cuffs.
Detachable sherpa knit spread collar.
Zip and hidden snap front.
Snap-flap patch pockets at front.
Outer: 70% Wool, 30% Polyester.
Collar: 65% Polyester, 35% Acrylic.
Machine wash cold, gentle cycle, lay flat to dry.
$100, plus $10 shipping. Reasonable offers will be considered, so hit me up. Shipping to North America only for now. No returns accepted, so please review the above carefully before making your purchase!