What about using self-signed (and thereby untrusted) certificates?
Say I want to serve a static HTML website from a Google cloud storage over SSL. No way to do this for free with let's encrypt. 1 click and free with cloud flare.
Is there MITM chance between cloud flare and Google? Yes. For a static website with no login or input from users, seems safer than any free alternative I know of.
https://cloud.google.com/storage/docs/hosting-static-website
Gives you a site at your name.com
Only missing link is the HTTPS which you get with cloud flare