dear, EpicGames
Hi so your engine is very nice to use and easy witch helps me out a lot and I wanted to know if I could publish a game if i finished it. I just wanted to know if I had to pay you or not and whats the cost of paying you and stuff like that
From,
Game Maker 
I move thread to general discussion as this is not a feedback.
As for question it self, Epic does not publish games made in UE4, only assets in Unreal marketplace. Publishing the game is something you need to deal for yourself and there many ways you can do this.
I think his/her question is “is s/he must pay to epic” and “how much should s/he pay to epic when s/he sold the games?”
I think the answer is Yes,
How much? -> 5% royalty from gross profit after First $3000
@Awesometosome , you should read FAQs/EULA, it will help you 