Bid Allies via eBay offers the refurbished Apple iPhone 4 16GB for Verizon Wireless in Black, model no. MC676LL/A, for $104.95 with free shipping. That's $70 under the cost of a new no-contract phone, although we saw a refurb for $7 less two weeks ago.
Note that no warranty information is provided. Also, it's incompatible with the upcoming iOS 8 release.