Amazon has the 18" 14k White and Yellow Gold Reversible 5mm Omega Chain Necklace for $400 with free shipping.
Amazon.com Product Description
This reversible necklace, crafted in Italy, has a simple, elegant design that fools the eye. It has the look of a solid piece of gold. In fact, it is made up of many small seamlessly-linked rectangular pieces of smooth polished 14 karat gold—yellow on one side and white on the other. While the design creates a solid look, the necklace is actually luxuriously smooth, flexible, and supple. It is contoured so that it drapes the neck beautifully. Choose the white or yellow gold side, depending on the color of the other jewelry you’re wearing with it. The necklace measures 18 inches and fastens with a lobster-claw clasp.
Amazon.com: 14k White and Yellow Gold Reversible 5mm Omega Chain Necklace, 18": Jewelry
18" 14k White and Yellow Gold Reversible 5mm Omega Chain Necklace $400 + FS 
