When following orangekiwi's link I noticed that The Outlaws of Sherwood, also by Robin McKinley, is $1.99 as well.
http://www.amazon.com/The-Outlaws-Sh...4K7NDDHBPS39DT
As you probably figured out from the name, it's a modern retelling of the Robin Hood story. It's been a while, but I quite enjoyed it when I read it around the time it was published.