$19 per month subscription for Unreal Engine 4 (plus a 5% royalty on released games)
For $19/month you can have access to everything, including the Unreal Editor in ready-to-run form, and the engine’s complete C++ source code hosted on GitHub for collaborative development.
This is the complete technology we at Epic use when building our own games, forged by years of experience shipping games like Gears of War for Xbox and Infinity Blade for iOS, and now reinvented for a new generation. Having the full C++ source provides the ultimate flexibility and puts developers in control of their schedules and destinies: Whatever you require to build and ship your game, you can find it in UE4, source it in the GitHub community, or build it yourself – and then share it with others.