If you're budget-restricted, this Marc Jacobs Pendant will fit the bill. It's a foolproof choice, while not very expensive. Another strong contender for your wardrobe is this Marc Jacobs Bracelet. While the price of this product is competitive, it will surely attract a lot of attention.
If you're looking for an item in the middle of the price range, look no further than this Marc Jacobs Brooch. This item doesn't cost a fortune, but absolutely deserves a spot in your wardrobe. Also check out this Marc Jacobs Necklace. It's an attractive option both price and quality-wise.