Amazon continues to offer downloads of Joseph Conrad's Heart of Darkness Kindle eBook bundled with Audible narration for free. (Check the box next to "Add Audible narration" on the product page to receive it.) That's tied with our mention from last week and a buck under the lowest price we could find for a digital download without narration, excluding the below mentions.
No interest in the narration? Barnes & Noble, iTunes, and Google Play have digital downloads without narration for free.