Flat Caps from 6pm.com
If you're not planning on spending much, your best bet is this Obey Flat Cap. It's a fantastic product, while not very costly. Another strong contender for your wardrobe is this Michael Stars Flat Cap. While the price of this item is rather reasonable, it will certainly attract a lot of attention. Or you can choose this Lauren Ralph Lauren Driver Cap - be sure you'll be making a stylish addition to your wardrobe.
If you're looking for an item in the middle of the price range, look no further than this Hat Attack Newsboy Cap. This item doesn't cost too much, but absolutely deserves a spot in your wardrobe.