SF Signal has an article called
"300 Science Fiction, Fantasy and Horror Kindle eBook Deals $3.99 or Less."
There are some big authors and very famous works in that list. I guess I should start following SF Signal more often.
BTW their article does use affiliate links, so if you like the site and want to support SF Signal, use their links. If you're not into affiliate links, just type in the titles yourself on Amazon.