Grey Beanies from shoptiques.com
If you're a thrifty spender, this Knitted Hat will fit the bill. It's a great choice, while not very expensive. In this price range, you can also check out this Herschel Knitted Hat. It's also a popular item and won't break the bank. You might also want to consider this Threads 4 Thought Beanie Hat. The price is very reasonable, but the effect on your wardrobe will be pretty fantastic.
If you're looking for an item in the middle of the price range, we've got your back with this White + Warren Beanie. This piece is bound to become a total wardrobe staple.