Ebay offers Sony SEL16F28 16mm f/2.8 Wide-Angle Lens for NEX Series Cameras for $161 (reg. $249.99) with free shipping. 

Product Description:
The Sony SEL 16F28 is a versatile and portable lens that works for shooting either still photography or video. The bright lens fits the Sony's NEX-series cameras and has a 16-millimeter focal length as well as an f/2.8 maximum aperture. It is also the equivalent of a 35-millimeter wide-angle lens, providing an impressive 83-degree field of view, which means solid low-light performance and a very quiet auto-focus operation. For more experienced photographers, this Sony wide-angle lens also offers manual focus so you can fine-tune the shot to your exact specifications. The lens comes with a specialized circular aperture, which offers a smoother and more natural look.