The "I Am Hungry" Facebook application was sold on eBay yesterday for $20,100. The application has 250K+ installs and records of some 150K users (the number of daily active users is under 1000), which means that user records in the deal went for $0.13 apiece. The price is in line with the valuation estimate on Adonomics.
From the eBay description: "Buying "I am hungry" will give you access to a quarter of a million users that are just waiting to be energized and attracted to the application. If your company has related products such as ordering food online or restaurant guides, buying this application and investing some time to improve it would give you a jumpstart in the Facebook application world."