If you can’t spend much, your best bet is this Neiman Marcus Overcoat. It's a popular piece, while not very costly. Another strong contender for your wardrobe is this Helmut Lang Coat. While the price of this item is rather reasonable, it will definitely attract a lot of attention. You might also want to consider this Vince Coat. The price is very reasonable, but the effect on your wardrobe will be pretty fantastic.