If you're a thrifty shopper, your best bet is this BaubleBar Necklace. It's a wonderful product, while not very costly. Another strong contender for your wardrobe is this Shourouk Necklace. While the price of this item is rather reasonable, it will certainly attract a lot of attention. Or you can choose this LuLu*s Choker Necklace - be sure you'll be making a stylish addition to your wardrobe.
If you're a bargain hunter, consider this Goti Necklace. While the price is very reasonable, this product is an easy wardrobe update.