Blinq via Amazon offers the Corkcicle Chillsner Beer Chiller 2-Pack, model no. 4002, for $16.49 with free shipping. Excluding other Amazon vendors and the below mention, that's the best deal we could find by $10 and the lowest total price we've seen. Each drink-through chiller is made of stainless steel and fits into most long-neck bottles.
A close price: Savebyus via eBay offers it for $16.99 with free shipping.