If you are on a budget, your best bet is this Diesel Beanie. It's a great piece, while not very costly. In this price range, you can also look at this Diesel Hat. It's also a popular item and won't break the bank.
If you're looking for a happy medium, we've got your back with this Diesel Bandana. This piece is likely to become a total wardrobe staple. You might also want to take a look at this Diesel Beanie. It's an attractive option both price and quality-wise.