If you're not planning on spending much, your best bet is this Donni Charm Bandana. It's a popular piece, while not very pricey. In this price range, you can also look at this Portolano Beret. It's also a popular item and won't break the bank. Or you can opt for this Rag & Bone Hat. This item has all the potential to become a powerful player in your wardrobe.
If you're looking to purchase a designer item, then what you're looking for is this Prada Baseball Cap. It's more expensive but worth your money. Another product we're drooling over is this Eugenia Kim Beret. It's costly but you get what you pay for. And one more item you might be interested in is this Eric Javits Beret. 'Cause you deserve nothing but all the finer things!