YouBuyRite via eBay offers the refurbished Unlocked Apple iPhone 4S 16GB Worldphone for GSM Networks in Black, model no. MD234LL/A, or White, model no. MD237LL/A, for $268.88 with free shipping. That's $31 under our mention from a week ago and the lowest total price we've seen for an unlocked 16GB iPhone 4S. (It's also the best deal we could find today by $5.) It's compatible with GSM networks such as AT&T, T-Mobile, and Vodafone; it can't be used with CDMA networks such as Verizon or Sprint. Deal ends August 14.
Note that no warranty information is provided.