Note that you can't use a free Cloudflare account just for things like images, video and other binary files, as they'll suspend the account. It must be used primarily for a website, not content hosting. If you only want to use Cloudflare for files, you need a paid account.
Five dollars a month, fixed, yes. fortepan.hu does this, it's a few terabytes of Hungarian historic photos. The site couldn't exist as it does now without Cloudflare essentially donating the bandwidth.
