Cheap book shops are one of the world's great mysteries and joys. Fly by Night by Frances Hardinge is the best book I've read for a long long time. It was on the discount table. Go figure.
An oddly ironic place given the nature of the book itself and the free exchange of ideas and literature.
Orphaned daughter of an exiled intellectual, Mosca Mye runs away from home, pausing only to collect her sidekick, a pugnacious gander, and to burn her uncle's mill to the ground in vengeful remembrance of things past. An overheard conversation sends her to rescue a travelling con-artist from the stocks, in the belief that he might prove useful to her, and together they leave the waterlogged village of Chough, where the petrifying springs bleach everything chalk-white, and head for a life of opportunity in the riverside towns and cities of the Fractured Kingdom.
.. from a rather sour review in the Guardian by Jan Mark. The Written Nerd has a more interesting review (to my mind) as he/she likes the book and is comparing two recent childrens works around the theme of censorship. Fly by Night and The Lost Colony by Grady Klein.
Strange Horizons' review by Farah Mendelsohn touches upon Fly by Night in a review for Hardinge's more recent book, Verdigris.