Cell Expert via eBay offers this 3-in-1 Universal Clip Lens Kit in Black/Red for $2.26 with free shipping. That's a buck under our May mention and the lowest total price we've seen. (It's also a current low by a buck, excluding the mention below.) It includes fisheye, wide angle, and macro interchangeable lenses that can be clipped to most mobile devices, including iPhones and Samsung Galaxy phones.

A close price: Pretty Cool via Amazon offers it for $2.71 with free shipping.