If you're on a thrifty mission, your best bet is this Boohoo Duster Coat. It's a great product, while not very pricey. Another strong contender for your wardrobe is this Missguided Duster Coat. While the price of this piece is not too high, it will definitely attract a lot of attention. You may also want to look at this Missguided Duster. This item is not expensive either, but it will make a difference in your wardrobe.
If you can afford to spend a little more, we've got your back with this Boutique Duster. This product is likely to become a total wardrobe staple.