Epic changed their licensing agreements this year and they favor smaller developers and those who want to focus on a game as opposed to an engine.
Unreal 4 is now $19 / mo with 5% royalties on gross income. However, if you cancel you can still use all of the source and engine to do what you want but you do not get updates. When you see an update you want, re-subscribe and pay $19 and get the update.
I've heard CRYENGINE is now about $12 / mo with limited source access. It is also available on Steam.
With all of the popular game engines changing their licensing models there isn't any reason not to try them.