I'm no expert, but as I understand it most jewelry such as necklaces are designed to be pretty, sparkling things, usually made from fancy, expensive materials like gold and diamonds. That's why they're so expensive. But I guess that's not always the case.
This Zipper Necklace isn't made out of any precious materials. In fact, it's made out of one of those elements of clothing we take for granted: the zipper. It repurposes tons of zippers, turning utilitarian function into a beautiful looking piece of wearable art. Each one is handmade to order, but due to the lack of expensive materials you've got to assume it's not too expensive. Diamonds are so last year anyways.