Amazon offers downloads of Emily Bronte's Wuthering Heights Kindle eBook for free. (Barnes & Noble charge the same for the Nook version.) That's $4 under the lowest price we could find for a paperback edition. It tells the classic story of Heathcliff and Catherine and their romance on the English moors.
Amazon offers downloads of John Grisham's The Tumor Kindle eBook for free. (Barnes & Noble also offers it for Nook devices for the same price.) That's tied with our mention from December (although that one wasn't available on Kindle) and the lowest price we could find now by $2.